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path: root/arch/arm/kvm/mmu.c
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2015-04-16Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "Here are the core arm64 updates for 4.1. Highlights include a significant rework to head.S (allowing us to boot on machines with physical memory at a really high address), an AES performance boost on Cortex-A57 and the ability to run a 32-bit userspace with 64k pages (although this requires said userspace to be built with a recent binutils). The head.S rework spilt over into KVM, so there are some changes under arch/arm/ which have been acked by Marc Zyngier (KVM co-maintainer). In particular, the linker script changes caused us some issues in -next, so there are a few merge commits where we had to apply fixes on top of a stable branch. Other changes include: - AES performance boost for Cortex-A57 - AArch32 (compat) userspace with 64k pages - Cortex-A53 erratum workaround for #845719 - defconfig updates (new platforms, PCI, ...)" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (39 commits) arm64: fix midr range for Cortex-A57 erratum 832075 arm64: errata: add workaround for cortex-a53 erratum #845719 arm64: Use bool function return values of true/false not 1/0 arm64: defconfig: updates for 4.1 arm64: Extract feature parsing code from cpu_errata.c arm64: alternative: Allow immediate branch as alternative instruction arm64: insn: Add aarch64_insn_decode_immediate ARM: kvm: round HYP section to page size instead of log2 upper bound ARM: kvm: assert on HYP section boundaries not actual code size arm64: head.S: ensure idmap_t0sz is visible arm64: pmu: add support for interrupt-affinity property dt: pmu: extend ARM PMU binding to allow for explicit interrupt affinity arm64: head.S: ensure visibility of page tables arm64: KVM: use ID map with increased VA range if required arm64: mm: increase VA range of identity map ARM: kvm: implement replacement for ld's LOG2CEIL() arm64: proc: remove unused cpu_get_pgd macro arm64: enforce x1|x2|x3 == 0 upon kernel entry as per boot protocol arm64: remove __calc_phys_offset arm64: merge __enable_mmu and __turn_mmu_on ...
2015-04-07Merge tag 'kvm-arm-for-4.1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into 'kvm-next' KVM/ARM changes for v4.1: - fixes for live migration - irqfd support - kvm-io-bus & vgic rework to enable ioeventfd - page ageing for stage-2 translation - various cleanups
2015-03-23arm64: KVM: use ID map with increased VA range if requiredArd Biesheuvel
This patch modifies the HYP init code so it can deal with system RAM residing at an offset which exceeds the reach of VA_BITS. Like for EL1, this involves configuring an additional level of translation for the ID map. However, in case of EL2, this implies that all translations use the extra level, as we cannot seamlessly switch between translation tables with different numbers of translation levels. So add an extra translation table at the root level. Since the ID map and the runtime HYP map are guaranteed not to overlap, they can share this root level, and we can essentially merge these two tables into one. Tested-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-19ARM, arm64: kvm: get rid of the bounce pageArd Biesheuvel
The HYP init bounce page is a runtime construct that ensures that the HYP init code does not cross a page boundary. However, this is something we can do perfectly well at build time, by aligning the code appropriately. For arm64, we just align to 4 KB, and enforce that the code size is less than 4 KB, regardless of the chosen page size. For ARM, the whole code is less than 256 bytes, so we tweak the linker script to align at a power of 2 upper bound of the code size Note that this also fixes a benign off-by-one error in the original bounce page code, where a bounce page would be allocated unnecessarily if the code was exactly 1 page in size. On ARM, it also fixes an issue with very large kernels reported by Arnd Bergmann, where stub sections with linker emitted veneers could erroneously trigger the size/alignment ASSERT() in the linker script. Tested-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-12arm/arm64: KVM: Optimize handling of Access Flag faultsMarc Zyngier
Now that we have page aging in Stage-2, it becomes obvious that we're doing way too much work handling the fault. The page is not going anywhere (it is still mapped), the page tables are already allocated, and all we want is to flip a bit in the PMD or PTE. Also, we can avoid any form of TLB invalidation, since a page with the AF bit off is not allowed to be cached. An obvious solution is to have a separate handler for FSC_ACCESS, where we pride ourselves to only do the very minimum amount of work. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-12arm/arm64: KVM: Implement Stage-2 page agingMarc Zyngier
Until now, KVM/arm didn't care much for page aging (who was swapping anyway?), and simply provided empty hooks to the core KVM code. With server-type systems now being available, things are quite different. This patch implements very simple support for page aging, by clearing the Access flag in the Stage-2 page tables. On access fault, the current fault handling will write the PTE or PMD again, putting the Access flag back on. It should be possible to implement a much faster handling for Access faults, but that's left for a later patch. With this in place, performance in VMs is degraded much more gracefully. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-12arm/arm64: KVM: Allow handle_hva_to_gpa to return a valueMarc Zyngier
So far, handle_hva_to_gpa was never required to return a value. As we prepare to age pages at Stage-2, we need to be able to return a value from the iterator (kvm_test_age_hva). Adapt the code to handle this situation. No semantic change. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-11arm64: KVM: Do not use pgd_index to index stage-2 pgdMarc Zyngier
The kernel's pgd_index macro is designed to index a normal, page sized array. KVM is a bit diffferent, as we can use concatenated pages to have a bigger address space (for example 40bit IPA with 4kB pages gives us an 8kB PGD. In the above case, the use of pgd_index will always return an index inside the first 4kB, which makes a guest that has memory above 0x8000000000 rather unhappy, as it spins forever in a page fault, whist the host happilly corrupts the lower pgd. The obvious fix is to get our own kvm_pgd_index that does the right thing(tm). Tested on X-Gene with a hacked kvmtool that put memory at a stupidly high address. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-11arm64: KVM: Fix stage-2 PGD allocation to have per-page refcountingMarc Zyngier
We're using __get_free_pages with to allocate the guest's stage-2 PGD. The standard behaviour of this function is to return a set of pages where only the head page has a valid refcount. This behaviour gets us into trouble when we're trying to increment the refcount on a non-head page: page:ffff7c00cfb693c0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x4000000000000000() page dumped because: VM_BUG_ON_PAGE((*({ __attribute__((unused)) typeof((&page->_count)->counter) __var = ( typeof((&page->_count)->counter)) 0; (volatile typeof((&page->_count)->counter) *)&((&page->_count)->counter); })) <= 0) BUG: failure at include/linux/mm.h:548/get_page()! Kernel panic - not syncing: BUG! CPU: 1 PID: 1695 Comm: kvm-vcpu-0 Not tainted 4.0.0-rc1+ #3825 Hardware name: APM X-Gene Mustang board (DT) Call trace: [<ffff80000008a09c>] dump_backtrace+0x0/0x13c [<ffff80000008a1e8>] show_stack+0x10/0x1c [<ffff800000691da8>] dump_stack+0x74/0x94 [<ffff800000690d78>] panic+0x100/0x240 [<ffff8000000a0bc4>] stage2_get_pmd+0x17c/0x2bc [<ffff8000000a1dc4>] kvm_handle_guest_abort+0x4b4/0x6b0 [<ffff8000000a420c>] handle_exit+0x58/0x180 [<ffff80000009e7a4>] kvm_arch_vcpu_ioctl_run+0x114/0x45c [<ffff800000099df4>] kvm_vcpu_ioctl+0x2e0/0x754 [<ffff8000001c0a18>] do_vfs_ioctl+0x424/0x5c8 [<ffff8000001c0bfc>] SyS_ioctl+0x40/0x78 CPU0: stopping A possible approach for this is to split the compound page using split_page() at allocation time, and change the teardown path to free one page at a time. It turns out that alloc_pages_exact() and free_pages_exact() does exactly that. While we're at it, the PGD allocation code is reworked to reduce duplication. This has been tested on an X-Gene platform with a 4kB/48bit-VA host kernel, and kvmtool hacked to place memory in the second page of the hardware PGD (PUD for the host kernel). Also regression-tested on a Cubietruck (Cortex-A7). [ Reworked to use alloc_pages_exact() and free_pages_exact() and to return pointers directly instead of by reference as arguments - Christoffer ] Reported-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-02-13Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM update from Paolo Bonzini: "Fairly small update, but there are some interesting new features. Common: Optional support for adding a small amount of polling on each HLT instruction executed in the guest (or equivalent for other architectures). This can improve latency up to 50% on some scenarios (e.g. O_DSYNC writes or TCP_RR netperf tests). This also has to be enabled manually for now, but the plan is to auto-tune this in the future. ARM/ARM64: The highlights are support for GICv3 emulation and dirty page tracking s390: Several optimizations and bugfixes. Also a first: a feature exposed by KVM (UUID and long guest name in /proc/sysinfo) before it is available in IBM's hypervisor! :) MIPS: Bugfixes. x86: Support for PML (page modification logging, a new feature in Broadwell Xeons that speeds up dirty page tracking), nested virtualization improvements (nested APICv---a nice optimization), usual round of emulation fixes. There is also a new option to reduce latency of the TSC deadline timer in the guest; this needs to be tuned manually. Some commits are common between this pull and Catalin's; I see you have already included his tree. Powerpc: Nothing yet. The KVM/PPC changes will come in through the PPC maintainers, because I haven't received them yet and I might end up being offline for some part of next week" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (130 commits) KVM: ia64: drop kvm.h from installed user headers KVM: x86: fix build with !CONFIG_SMP KVM: x86: emulate: correct page fault error code for NoWrite instructions KVM: Disable compat ioctl for s390 KVM: s390: add cpu model support KVM: s390: use facilities and cpu_id per KVM KVM: s390/CPACF: Choose crypto control block format s390/kernel: Update /proc/sysinfo file with Extended Name and UUID KVM: s390: reenable LPP facility KVM: s390: floating irqs: fix user triggerable endless loop kvm: add halt_poll_ns module parameter kvm: remove KVM_MMIO_SIZE KVM: MIPS: Don't leak FPU/DSP to guest KVM: MIPS: Disable HTW while in guest KVM: nVMX: Enable nested posted interrupt processing KVM: nVMX: Enable nested virtual interrupt delivery KVM: nVMX: Enable nested apic register virtualization KVM: nVMX: Make nested control MSRs per-cpu KVM: nVMX: Enable nested virtualize x2apic mode KVM: nVMX: Prepare for using hardware MSR bitmap ...
2015-01-29arm/arm64: KVM: Use kernel mapping to perform invalidation on page faultMarc Zyngier
When handling a fault in stage-2, we need to resync I$ and D$, just to be sure we don't leave any old cache line behind. That's very good, except that we do so using the *user* address. Under heavy load (swapping like crazy), we may end up in a situation where the page gets mapped in stage-2 while being unmapped from userspace by another CPU. At that point, the DC/IC instructions can generate a fault, which we handle with kvm->mmu_lock held. The box quickly deadlocks, user is unhappy. Instead, perform this invalidation through the kernel mapping, which is guaranteed to be present. The box is much happier, and so am I. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-29arm/arm64: KVM: Invalidate data cache on unmapMarc Zyngier
Let's assume a guest has created an uncached mapping, and written to that page. Let's also assume that the host uses a cache-coherent IO subsystem. Let's finally assume that the host is under memory pressure and starts to swap things out. Before this "uncached" page is evicted, we need to make sure we invalidate potential speculated, clean cache lines that are sitting there, or the IO subsystem is going to swap out the cached view, loosing the data that has been written directly into memory. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-29arm/arm64: KVM: Use set/way op trapping to track the state of the cachesMarc Zyngier
Trying to emulate the behaviour of set/way cache ops is fairly pointless, as there are too many ways we can end-up missing stuff. Also, there is some system caches out there that simply ignore set/way operations. So instead of trying to implement them, let's convert it to VA ops, and use them as a way to re-enable the trapping of VM ops. That way, we can detect the point when the MMU/caches are turned off, and do a full VM flush (which is what the guest was trying to do anyway). This allows a 32bit zImage to boot on the APM thingy, and will probably help bootloaders in general. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-29KVM: Rename kvm_arch_mmu_write_protect_pt_masked to be more generic for log ↵Kai Huang
dirty We don't have to write protect guest memory for dirty logging if architecture supports hardware dirty logging, such as PML on VMX, so rename it to be more generic. Signed-off-by: Kai Huang <kai.huang@linux.intel.com> Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-23arm/arm64: KVM: Fixup incorrect config symbol in commentChristoffer Dall
A comment in the dirty page logging patch series mentioned incorrectly spelled config symbols, just fix them up to match the real thing. Reported-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-16KVM: arm/arm64: Enable Dirty Page logging for ARMv8Mario Smarduch
This patch enables ARMv8 ditry page logging support. Plugs ARMv8 into generic layer through Kconfig symbol, and drops earlier ARM64 constraints to enable logging at architecture layer. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
2015-01-16KVM: arm: page logging 2nd stage fault handlingMario Smarduch
This patch adds support for 2nd stage page fault handling while dirty page logging. On huge page faults, huge pages are dissolved to normal pages, and rebuilding of 2nd stage huge pages is blocked. In case migration is canceled this restriction is removed and huge pages may be rebuilt again. Signed-off-by: Mario Smarduch <m.smarduch@samsung.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-16KVM: arm: dirty logging write protect supportMario Smarduch
Add support to track dirty pages between user space KVM_GET_DIRTY_LOG ioctl calls. We call kvm_get_dirty_log_protect() function to do most of the work. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
2015-01-16KVM: arm: Add initial dirty page locking supportMario Smarduch
Add support for initial write protection of VM memslots. This patch series assumes that huge PUDs will not be used in 2nd stage tables, which is always valid on ARMv7 Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
2014-12-19Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM update from Paolo Bonzini: "3.19 changes for KVM: - spring cleaning: removed support for IA64, and for hardware- assisted virtualization on the PPC970 - ARM, PPC, s390 all had only small fixes For x86: - small performance improvements (though only on weird guests) - usual round of hardware-compliancy fixes from Nadav - APICv fixes - XSAVES support for hosts and guests. XSAVES hosts were broken because the (non-KVM) XSAVES patches inadvertently changed the KVM userspace ABI whenever XSAVES was enabled; hence, this part is going to stable. Guest support is just a matter of exposing the feature and CPUID leaves support" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (179 commits) KVM: move APIC types to arch/x86/ KVM: PPC: Book3S: Enable in-kernel XICS emulation by default KVM: PPC: Book3S HV: Improve H_CONFER implementation KVM: PPC: Book3S HV: Fix endianness of instruction obtained from HEIR register KVM: PPC: Book3S HV: Remove code for PPC970 processors KVM: PPC: Book3S HV: Tracepoints for KVM HV guest interactions KVM: PPC: Book3S HV: Simplify locking around stolen time calculations arch: powerpc: kvm: book3s_paired_singles.c: Remove unused function arch: powerpc: kvm: book3s_pr.c: Remove unused function arch: powerpc: kvm: book3s.c: Remove some unused functions arch: powerpc: kvm: book3s_32_mmu.c: Remove unused function KVM: PPC: Book3S HV: Check wait conditions before sleeping in kvmppc_vcore_blocked KVM: PPC: Book3S HV: ptes are big endian KVM: PPC: Book3S HV: Fix inaccuracies in ICP emulation for H_IPI KVM: PPC: Book3S HV: Fix KSM memory corruption KVM: PPC: Book3S HV: Fix an issue where guest is paused on receiving HMI KVM: PPC: Book3S HV: Fix computation of tlbie operand KVM: PPC: Book3S HV: Add missing HPTE unlock KVM: PPC: BookE: Improve irq inject tracepoint arm/arm64: KVM: Require in-kernel vgic for the arch timers ...
2014-12-13arm/arm64: KVM: Introduce stage2_unmap_vmChristoffer Dall
Introduce a new function to unmap user RAM regions in the stage2 page tables. This is needed on reboot (or when the guest turns off the MMU) to ensure we fault in pages again and make the dcache, RAM, and icache coherent. Using unmap_stage2_range for the whole guest physical range does not work, because that unmaps IO regions (such as the GIC) which will not be recreated or in the best case faulted in on a page-by-page basis. Call this function on secondary and subsequent calls to the KVM_ARM_VCPU_INIT ioctl so that a reset VCPU will detect the guest Stage-1 MMU is off when faulting in pages and make the caches coherent. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-11-26arm/arm64: kvm: drop inappropriate use of kvm_is_mmio_pfn()Ard Biesheuvel
Instead of using kvm_is_mmio_pfn() to decide whether a host region should be stage 2 mapped with device attributes, add a new static function kvm_is_device_pfn() that disregards RAM pages with the reserved bit set, as those should usually not be mapped as device memory. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-26arm64: KVM: fix unmapping with 48-bit VAsMark Rutland
Currently if using a 48-bit VA, tearing down the hyp page tables (which can happen in the absence of a GICH or GICV resource) results in the rather nasty splat below, evidently becasue we access a table that doesn't actually exist. Commit 38f791a4e499792e (arm64: KVM: Implement 48 VA support for KVM EL2 and Stage-2) added a pgd_none check to __create_hyp_mappings to account for the additional level of tables, but didn't add a corresponding check to unmap_range, and this seems to be the source of the problem. This patch adds the missing pgd_none check, ensuring we don't try to access tables that don't exist. Original splat below: kvm [1]: Using HYP init bounce page @83fe94a000 kvm [1]: Cannot obtain GICH resource Unable to handle kernel paging request at virtual address ffff7f7fff000000 pgd = ffff800000770000 [ffff7f7fff000000] *pgd=0000000000000000 Internal error: Oops: 96000004 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.18.0-rc2+ #89 task: ffff8003eb500000 ti: ffff8003eb45c000 task.ti: ffff8003eb45c000 PC is at unmap_range+0x120/0x580 LR is at free_hyp_pgds+0xac/0xe4 pc : [<ffff80000009b768>] lr : [<ffff80000009cad8>] pstate: 80000045 sp : ffff8003eb45fbf0 x29: ffff8003eb45fbf0 x28: ffff800000736000 x27: ffff800000735000 x26: ffff7f7fff000000 x25: 0000000040000000 x24: ffff8000006f5000 x23: 0000000000000000 x22: 0000007fffffffff x21: 0000800000000000 x20: 0000008000000000 x19: 0000000000000000 x18: ffff800000648000 x17: ffff800000537228 x16: 0000000000000000 x15: 000000000000001f x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000020 x11: 0000000000000062 x10: 0000000000000006 x9 : 0000000000000000 x8 : 0000000000000063 x7 : 0000000000000018 x6 : 00000003ff000000 x5 : ffff800000744188 x4 : 0000000000000001 x3 : 0000000040000000 x2 : ffff800000000000 x1 : 0000007fffffffff x0 : 000000003fffffff Process swapper/0 (pid: 1, stack limit = 0xffff8003eb45c058) Stack: (0xffff8003eb45fbf0 to 0xffff8003eb460000) fbe0: eb45fcb0 ffff8003 0009cad8 ffff8000 fc00: 00000000 00000080 00736140 ffff8000 00736000 ffff8000 00000000 00007c80 fc20: 00000000 00000080 006f5000 ffff8000 00000000 00000080 00743000 ffff8000 fc40: 00735000 ffff8000 006d3030 ffff8000 006fe7b8 ffff8000 00000000 00000080 fc60: ffffffff 0000007f fdac1000 ffff8003 fd94b000 ffff8003 fda47000 ffff8003 fc80: 00502b40 ffff8000 ff000000 ffff7f7f fdec6000 00008003 fdac1630 ffff8003 fca0: eb45fcb0 ffff8003 ffffffff 0000007f eb45fd00 ffff8003 0009b378 ffff8000 fcc0: ffffffea 00000000 006fe000 ffff8000 00736728 ffff8000 00736120 ffff8000 fce0: 00000040 00000000 00743000 ffff8000 006fe7b8 ffff8000 0050cd48 00000000 fd00: eb45fd60 ffff8003 00096070 ffff8000 006f06e0 ffff8000 006f06e0 ffff8000 fd20: fd948b40 ffff8003 0009a320 ffff8000 00000000 00000000 00000000 00000000 fd40: 00000ae0 00000000 006aa25c ffff8000 eb45fd60 ffff8003 0017ca44 00000002 fd60: eb45fdc0 ffff8003 0009a33c ffff8000 006f06e0 ffff8000 006f06e0 ffff8000 fd80: fd948b40 ffff8003 0009a320 ffff8000 00000000 00000000 00735000 ffff8000 fda0: 006d3090 ffff8000 006aa25c ffff8000 00735000 ffff8000 006d3030 ffff8000 fdc0: eb45fdd0 ffff8003 000814c0 ffff8000 eb45fe50 ffff8003 006aaac4 ffff8000 fde0: 006ddd90 ffff8000 00000006 00000000 006d3000 ffff8000 00000095 00000000 fe00: 006a1e90 ffff8000 00735000 ffff8000 006d3000 ffff8000 006aa25c ffff8000 fe20: 00735000 ffff8000 006d3030 ffff8000 eb45fe50 ffff8003 006fac68 ffff8000 fe40: 00000006 00000006 fe293ee6 ffff8003 eb45feb0 ffff8003 004f8ee8 ffff8000 fe60: 004f8ed4 ffff8000 00735000 ffff8000 00000000 00000000 00000000 00000000 fe80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 fea0: 00000000 00000000 00000000 00000000 00000000 00000000 000843d0 ffff8000 fec0: 004f8ed4 ffff8000 00000000 00000000 00000000 00000000 00000000 00000000 fee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ffa0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000005 00000000 ffe0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 Call trace: [<ffff80000009b768>] unmap_range+0x120/0x580 [<ffff80000009cad4>] free_hyp_pgds+0xa8/0xe4 [<ffff80000009b374>] kvm_arch_init+0x268/0x44c [<ffff80000009606c>] kvm_init+0x24/0x260 [<ffff80000009a338>] arm_init+0x18/0x24 [<ffff8000000814bc>] do_one_initcall+0x88/0x1a0 [<ffff8000006aaac0>] kernel_init_freeable+0x148/0x1e8 [<ffff8000004f8ee4>] kernel_init+0x10/0xd4 Code: 8b000263 92628479 d1000720 eb01001f (f9400340) ---[ end trace 3bc230562e926fa4 ]--- Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jungseok Lee <jungseoklee85@gmail.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-25arm, arm64: KVM: handle potential incoherency of readonly memslotsArd Biesheuvel
Readonly memslots are often used to implement emulation of ROMs and NOR flashes, in which case the guest may legally map these regions as uncached. To deal with the incoherency associated with uncached guest mappings, treat all readonly memslots as incoherent, and ensure that pages that belong to regions tagged as such are flushed to DRAM before being passed to the guest. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-11-25arm, arm64: KVM: allow forced dcache flush on page faultsLaszlo Ersek
To allow handling of incoherent memslots in a subsequent patch, this patch adds a paramater 'ipa_uncached' to cache_coherent_guest_page() so that we can instruct it to flush the page's contents to DRAM even if the guest has caching globally enabled. Signed-off-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-11-25arm/arm64: kvm: drop inappropriate use of kvm_is_mmio_pfn()Ard Biesheuvel
Instead of using kvm_is_mmio_pfn() to decide whether a host region should be stage 2 mapped with device attributes, add a new static function kvm_is_device_pfn() that disregards RAM pages with the reserved bit set, as those should usually not be mapped as device memory. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-10-15arm: kvm: STRICT_MM_TYPECHECKS fix for user_mem_abortSteve Capper
Commit: b886576 ARM: KVM: user_mem_abort: support stage 2 MMIO page mapping introduced some code in user_mem_abort that failed to compile if STRICT_MM_TYPECHECKS was enabled. This patch fixes up the failing comparison. Signed-off-by: Steve Capper <steve.capper@linaro.org> Reviewed-by: Kim Phillips <kim.phillips@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-14arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZEChristoffer Dall
When creating or moving a memslot, make sure the IPA space is within the addressable range of the guest. Otherwise, user space can create too large a memslot and KVM would try to access potentially unallocated page table entries when inserting entries in the Stage-2 page tables. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-14arm64: KVM: Implement 48 VA support for KVM EL2 and Stage-2Christoffer Dall
This patch adds the necessary support for all host kernel PGSIZE and VA_SPACE configuration options for both EL2 and the Stage-2 page tables. However, for 40bit and 42bit PARange systems, the architecture mandates that VTCR_EL2.SL0 is maximum 1, resulting in fewer levels of stage-2 pagge tables than levels of host kernel page tables. At the same time, systems with a PARange > 42bit, we limit the IPA range by always setting VTCR_EL2.T0SZ to 24. To solve the situation with different levels of page tables for Stage-2 translation than the host kernel page tables, we allocate a dummy PGD with pointers to our actual inital level Stage-2 page table, in order for us to reuse the kernel pgtable manipulation primitives. Reproducing all these in KVM does not look pretty and unnecessarily complicates the 32-bit side. Systems with a PARange < 40bits are not yet supported. [ I have reworked this patch from its original form submitted by Jungseok to take the architecture constraints into consideration. There were too many changes from the original patch for me to preserve the authorship. Thanks to Catalin Marinas for his help in figuring out a good solution to this challenge. I have also fixed various bugs and missing error code handling from the original patch. - Christoffer ] Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-13arm/arm64: KVM: map MMIO regions at creation timeArd Biesheuvel
There is really no point in faulting in memory regions page by page if they are not backed by demand paged system RAM but by a linear passthrough mapping of a host MMIO region. So instead, detect such regions at setup time and install the mappings for the backing all at once. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-10arm/arm64: KVM: add 'writable' parameter to kvm_phys_addr_ioremapArd Biesheuvel
Add support for read-only MMIO passthrough mappings by adding a 'writable' parameter to kvm_phys_addr_ioremap. For the moment, mappings will be read-write even if 'writable' is false, but once the definition of PAGE_S2_DEVICE gets changed, those mappings will be created read-only. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-10arm/arm64: KVM: fix potential NULL dereference in user_mem_abort()Ard Biesheuvel
Handle the potential NULL return value of find_vma_intersection() before dereferencing it. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-10arm/arm64: KVM: use __GFP_ZERO not memset() to get zeroed pagesArd Biesheuvel
Pass __GFP_ZERO to __get_free_pages() instead of calling memset() explicitly. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-09-26arm/arm64: KVM: Report correct FSC for unsupported fault typesChristoffer Dall
When we catch something that's not a permission fault or a translation fault, we log the unsupported FSC in the kernel log, but we were masking off the bottom bits of the FSC which was not very helpful. Also correctly report the FSC for data and instruction faults rather than telling people it was a DFCS, which doesn't exist in the ARM ARM. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-09-11ARM/arm64: KVM: fix use of WnR bit in kvm_is_write_fault()Ard Biesheuvel
The ISS encoding for an exception from a Data Abort has a WnR bit[6] that indicates whether the Data Abort was caused by a read or a write instruction. While there are several fields in the encoding that are only valid if the ISV bit[24] is set, WnR is not one of them, so we can read it unconditionally. Instead of fixing both implementations of kvm_is_write_fault() in place, reimplement it just once using kvm_vcpu_dabt_iswrite(), which already does the right thing with respect to the WnR bit. Also fix up the callers to pass 'vcpu' Acked-by: Laszlo Ersek <lersek@redhat.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-08-27arm/arm64: KVM: Support KVM_CAP_READONLY_MEMChristoffer Dall
When userspace loads code and data in a read-only memory regions, KVM needs to be able to handle this on arm and arm64. Specifically this is used when running code directly from a read-only flash device; the common scenario is a UEFI blob loaded with the -bios option in QEMU. Note that the MMIO exit on writes to a read-only memory is ABI and can be used to emulate block-erase style flash devices. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-07-11ARM: KVM: user_mem_abort: support stage 2 MMIO page mappingKim Phillips
A userspace process can map device MMIO memory via VFIO or /dev/mem, e.g., for platform device passthrough support in QEMU. During early development, we found the PAGE_S2 memory type being used for MMIO mappings. This patch corrects that by using the more strongly ordered memory type for device MMIO mappings: PAGE_S2_DEVICE. Signed-off-by: Kim Phillips <kim.phillips@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-07-11ARM: KVM: Unmap IPA on memslot delete/moveEric Auger
Currently when a KVM region is deleted or moved after KVM_SET_USER_MEMORY_REGION ioctl, the corresponding intermediate physical memory is not unmapped. This patch corrects this and unmaps the region's IPA range in kvm_arch_commit_memory_region using unmap_stage2_range. Signed-off-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-07-11arm/arm64: KVM: Fix and refactor unmap_rangeChristoffer Dall
unmap_range() was utterly broken, to quote Marc, and broke in all sorts of situations. It was also quite complicated to follow and didn't follow the usual scheme of having a separate iterating function for each level of page tables. Address this by refactoring the code and introduce a pgd_clear() function. Reviewed-by: Jungseok Lee <jays.lee@samsung.com> Reviewed-by: Mario Smarduch <m.smarduch@samsung.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-04-28arm: KVM: fix possible misalignment of PGDs and bounce pageMark Salter
The kvm/mmu code shared by arm and arm64 uses kalloc() to allocate a bounce page (if hypervisor init code crosses page boundary) and hypervisor PGDs. The problem is that kalloc() does not guarantee the proper alignment. In the case of the bounce page, the page sized buffer allocated may also cross a page boundary negating the purpose and leading to a hang during kvm initialization. Likewise the PGDs allocated may not meet the minimum alignment requirements of the underlying MMU. This patch uses __get_free_page() to guarantee the worst case alignment needs of the bounce page and PGDs on both arm and arm64. Cc: <stable@vger.kernel.org> # 3.10+ Signed-off-by: Mark Salter <msalter@redhat.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-03-03ARM: KVM: fix warning in mmu.cMarc Zyngier
Compiling with THP enabled leads to the following warning: arch/arm/kvm/mmu.c: In function ‘unmap_range’: arch/arm/kvm/mmu.c:177:39: warning: ‘pte’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (kvm_pmd_huge(*pmd) || page_empty(pte)) { ^ Code inspection reveals that these two cases are mutually exclusive, so GCC is a bit overzealous here. Silence it anyway by initializing pte to NULL and testing it later on. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-03-03arm64: KVM: flush VM pages before letting the guest enable cachesMarc Zyngier
When the guest runs with caches disabled (like in an early boot sequence, for example), all the writes are diectly going to RAM, bypassing the caches altogether. Once the MMU and caches are enabled, whatever sits in the cache becomes suddenly visible, which isn't what the guest expects. A way to avoid this potential disaster is to invalidate the cache when the MMU is being turned on. For this, we hook into the SCTLR_EL1 trapping code, and scan the stage-2 page tables, invalidating the pages/sections that have already been mapped in. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-03-03ARM: KVM: introduce kvm_p*d_addr_endMarc Zyngier
The use of p*d_addr_end with stage-2 translation is slightly dodgy, as the IPA is 40bits, while all the p*d_addr_end helpers are taking an unsigned long (arm64 is fine with that as unligned long is 64bit). The fix is to introduce 64bit clean versions of the same helpers, and use them in the stage-2 page table code. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-03-03arm64: KVM: force cache clean on page fault when caches are offMarc Zyngier
In order for the guest with caches off to observe data written contained in a given page, we need to make sure that page is committed to memory, and not just hanging in the cache (as guest accesses are completely bypassing the cache until it decides to enable it). For this purpose, hook into the coherent_icache_guest_page function and flush the region if the guest SCTLR_EL1 register doesn't show the MMU and caches as being enabled. The function also get renamed to coherent_cache_guest_page. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-01-08arm/arm64: KVM: relax the requirements of VMA alignment for THPMarc Zyngier
The THP code in KVM/ARM is a bit restrictive in not allowing a THP to be used if the VMA is not 2MB aligned. Actually, it is not so much the VMA that matters, but the associated memslot: A process can perfectly mmap a region with no particular alignment restriction, and then pass a 2MB aligned address to KVM. In this case, KVM will only use this 2MB aligned region, and will ignore the range between vma->vm_start and memslot->userspace_addr. It can also choose to place this memslot at whatever alignment it wants in the IPA space. In the end, what matters is the relative alignment of the user space and IPA mappings with respect to a 2M page. They absolutely must be the same if you want to use THP. Cc: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-12-11arm/arm64: kvm: Use virt_to_idmap instead of virt_to_phys for idmap mappingsSantosh Shilimkar
KVM initialisation fails on architectures implementing virt_to_idmap() because virt_to_phys() on such architectures won't fetch you the correct idmap page. So update the KVM ARM code to use the virt_to_idmap() to fix the issue. Since the KVM code is shared between arm and arm64, we create kvm_virt_to_phys() and handle the redirection in respective headers. Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-11-19Merge tag 'kvm-arm-fixes-3.13-1' of ↵Gleb Natapov
git://git.linaro.org/people/cdall/linux-kvm-arm into next Fix percpu vmalloc allocations
2013-11-17arm/arm64: KVM: Fix hyp mappings of vmalloc regionsChristoffer Dall
Using virt_to_phys on percpu mappings is horribly wrong as it may be backed by vmalloc. Introduce kvm_kaddr_to_phys which translates both types of valid kernel addresses to the corresponding physical address. At the same time resolves a typing issue where we were storing the physical address as a 32 bit unsigned long (on arm), truncating the physical address for addresses above the 4GB limit. This caused breakage on Keystone. Cc: <stable@vger.kernel.org> [3.10+] Reported-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-10-18KVM: ARM: Transparent huge page (THP) supportChristoffer Dall
Support transparent huge pages in KVM/ARM and KVM/ARM64. The transparent_hugepage_adjust is not very pretty, but this is also how it's solved on x86 and seems to be simply an artifact on how THPs behave. This should eventually be shared across architectures if possible, but that can always be changed down the road. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-10-18KVM: ARM: Support hugetlbfs backed huge pagesChristoffer Dall
Support huge pages in KVM/ARM and KVM/ARM64. The pud_huge checking on the unmap path may feel a bit silly as the pud_huge check is always defined to false, but the compiler should be smart about this. Note: This deals only with VMAs marked as huge which are allocated by users through hugetlbfs only. Transparent huge pages can only be detected by looking at the underlying pages (or the page tables themselves) and this patch so far simply maps these on a page-by-page level in the Stage-2 page tables. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>