summaryrefslogtreecommitdiff
path: root/arch/x86/kvm/vmx.c
AgeCommit message (Collapse)Author
2016-08-18kvm: nVMX: fix nested tsc scalingPeter Feiner
When the host supported TSC scaling, L2 would use a TSC multiplier of 0, which causes a VM entry failure. Now L2's TSC uses the same multiplier as L1. Signed-off-by: Peter Feiner <pfeiner@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-08-18KVM: nVMX: postpone VMCS changes on MSR_IA32_APICBASE writeRadim Krčmář
If vmcs12 does not intercept APIC_BASE writes, then KVM will handle the write with vmcs02 as the current VMCS. This will incorrectly apply modifications intended for vmcs01 to vmcs02 and L2 can use it to gain access to L0's x2APIC registers by disabling virtualized x2APIC while using msr bitmap that assumes enabled. Postpone execution of vmx_set_virtual_x2apic_mode until vmcs01 is the current VMCS. An alternative solution would temporarily make vmcs01 the current VMCS, but it requires more care. Fixes: 8d14695f9542 ("x86, apicv: add virtual x2apic support") Reported-by: Jim Mattson <jmattson@google.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-18KVM: nVMX: fix msr bitmaps to prevent L2 from accessing L0 x2APICRadim Krčmář
msr bitmap can be used to avoid a VM exit (interception) on guest MSR accesses. In some configurations of VMX controls, the guest can even directly access host's x2APIC MSRs. See SDM 29.5 VIRTUALIZING MSR-BASED APIC ACCESSES. L2 could read all L0's x2APIC MSRs and write TPR, EOI, and SELF_IPI. To do so, L1 would first trick KVM to disable all possible interceptions by enabling APICv features and then would turn those features off; nested_vmx_merge_msr_bitmap() only disabled interceptions, so VMX would not intercept previously enabled MSRs even though they were not safe with the new configuration. Correctly re-enabling interceptions is not enough as a second bug would still allow L1+L2 to access host's MSRs: msr bitmap was shared for all VMCSs, so L1 could trigger a race to get the desired combination of msr bitmap and VMX controls. This fix allocates a msr bitmap for every L1 VCPU, allows only safe x2APIC MSRs from L1's msr bitmap, and disables msr bitmaps if they would have to intercept everything anyway. Fixes: 3af18d9c5fe9 ("KVM: nVMX: Prepare for using hardware MSR bitmap") Reported-by: Jim Mattson <jmattson@google.com> Suggested-by: Wincy Van <fanwenyi0529@gmail.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-04nvmx: mark ept single context invalidation as supportedBandan Das
Commit 4b855078601f ("KVM: nVMX: Don't advertise single context invalidation for invept") removed advertising single context invalidation since the spec does not mandate it. However, some hypervisors (such as ESX) require it to be present before willing to use ept in a nested environment. Advertise it and fallback to the global case. Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-08-04nvmx: remove comment about missing nested vpid supportBandan Das
Nested vpid is already supported and both single/global modes are advertised to the guest Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-08-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: - ARM: GICv3 ITS emulation and various fixes. Removal of the old VGIC implementation. - s390: support for trapping software breakpoints, nested virtualization (vSIE), the STHYI opcode, initial extensions for CPU model support. - MIPS: support for MIPS64 hosts (32-bit guests only) and lots of cleanups, preliminary to this and the upcoming support for hardware virtualization extensions. - x86: support for execute-only mappings in nested EPT; reduced vmexit latency for TSC deadline timer (by about 30%) on Intel hosts; support for more than 255 vCPUs. - PPC: bugfixes. * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (302 commits) KVM: PPC: Introduce KVM_CAP_PPC_HTM MIPS: Select HAVE_KVM for MIPS64_R{2,6} MIPS: KVM: Reset CP0_PageMask during host TLB flush MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX() MIPS: KVM: Sign extend MFC0/RDHWR results MIPS: KVM: Fix 64-bit big endian dynamic translation MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase MIPS: KVM: Use 64-bit CP0_EBase when appropriate MIPS: KVM: Set CP0_Status.KX on MIPS64 MIPS: KVM: Make entry code MIPS64 friendly MIPS: KVM: Use kmap instead of CKSEG0ADDR() MIPS: KVM: Use virt_to_phys() to get commpage PFN MIPS: Fix definition of KSEGX() for 64-bit KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLD kvm: x86: nVMX: maintain internal copy of current VMCS KVM: PPC: Book3S HV: Save/restore TM state in H_CEDE KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures KVM: arm64: vgic-its: Simplify MAPI error handling KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlers KVM: arm64: vgic-its: Turn device_id validation into generic ID validation ...
2016-08-01KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLDJim Mattson
Kexec needs to know the addresses of all VMCSs that are active on each CPU, so that it can flush them from the VMCS caches. It is safe to record superfluous addresses that are not associated with an active VMCS, but it is not safe to omit an address associated with an active VMCS. After a call to vmcs_load, the VMCS that was loaded is active on the CPU. The VMCS should be added to the CPU's list of active VMCSs before it is loaded. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-01kvm: x86: nVMX: maintain internal copy of current VMCSDavid Matlack
KVM maintains L1's current VMCS in guest memory, at the guest physical page identified by the argument to VMPTRLD. This makes hairy time-of-check to time-of-use bugs possible,as VCPUs can be writing the the VMCS page in memory while KVM is emulating VMLAUNCH and VMRESUME. The spec documents that writing to the VMCS page while it is loaded is "undefined". Therefore it is reasonable to load the entire VMCS into an internal cache during VMPTRLD and ignore writes to the VMCS page -- the guest should be using VMREAD and VMWRITE to access the current VMCS. To adhere to the spec, KVM should flush the current VMCS during VMPTRLD, and the target VMCS during VMCLEAR (as given by the operand to VMCLEAR). Since this implementation of VMCS caching only maintains the the current VMCS, VMCLEAR will only do a flush if the operand to VMCLEAR is the current VMCS pointer. KVM will also flush during VMXOFF, which is not mandated by the spec, but also not in conflict with the spec. Signed-off-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-29Merge tag 'libnvdimm-for-4.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: - Replace pcommit with ADR / directed-flushing. The pcommit instruction, which has not shipped on any product, is deprecated. Instead, the requirement is that platforms implement either ADR, or provide one or more flush addresses per nvdimm. ADR (Asynchronous DRAM Refresh) flushes data in posted write buffers to the memory controller on a power-fail event. Flush addresses are defined in ACPI 6.x as an NVDIMM Firmware Interface Table (NFIT) sub-structure: "Flush Hint Address Structure". A flush hint is an mmio address that when written and fenced assures that all previous posted writes targeting a given dimm have been flushed to media. - On-demand ARS (address range scrub). Linux uses the results of the ACPI ARS commands to track bad blocks in pmem devices. When latent errors are detected we re-scrub the media to refresh the bad block list, userspace can also request a re-scrub at any time. - Support for the Microsoft DSM (device specific method) command format. - Support for EDK2/OVMF virtual disk device memory ranges. - Various fixes and cleanups across the subsystem. * tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (41 commits) libnvdimm-btt: Delete an unnecessary check before the function call "__nd_device_register" nfit: do an ARS scrub on hitting a latent media error nfit: move to nfit/ sub-directory nfit, libnvdimm: allow an ARS scrub to be triggered on demand libnvdimm: register nvdimm_bus devices with an nd_bus driver pmem: clarify a debug print in pmem_clear_poison x86/insn: remove pcommit Revert "KVM: x86: add pcommit support" nfit, tools/testing/nvdimm/: unify shutdown paths libnvdimm: move ->module to struct nvdimm_bus_descriptor nfit: cleanup acpi_nfit_init calling convention nfit: fix _FIT evaluation memory leak + use after free tools/testing/nvdimm: add manufacturing_{date|location} dimm properties tools/testing/nvdimm: add virtual ramdisk range acpi, nfit: treat virtual ramdisk SPA as pmem region pmem: kill __pmem address space pmem: kill wmb_pmem() libnvdimm, pmem: use nvdimm_flush() for namespace I/O writes fs/dax: remove wmb_pmem() libnvdimm, pmem: flush posted-write queues on shutdown ...
2016-07-24Merge branch 'for-4.8/libnvdimm' into libnvdimm-for-nextDan Williams
2016-07-23Revert "KVM: x86: add pcommit support"Dan Williams
This reverts commit 8b3e34e46aca9b6d349b331cd9cf71ccbdc91b2e. Given the deprecation of the pcommit instruction, the relevant VMX features and CPUID bits are not going to be rolled into the SDM. Remove their usage from KVM. Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-07-16KVM: VMX: handle PML full VMEXIT that occurs during event deliveryCao, Lei
With PML enabled, guest will shut down if a PML full VMEXIT occurs during event delivery. According to Intel SDM 27.2.3, PML full VMEXIT can occur when event is being delivered through IDT, so KVM should not exit to user space with error. Instead, it should let EXIT_REASON_PML_FULL go through and the event will be re-injected on the next VMENTRY. Signed-off-by: Lei Cao <lei.cao@stratus.com> Cc: stable@vger.kernel.org Fixes: 843e4330573c ("KVM: VMX: Add PML support in VMX") [Shortened the summary and Cc'd stable.] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-07-14KVM: nVMX: Fix memory corruption when using VMCS shadowingJim Mattson
When freeing the nested resources of a vcpu, there is an assumption that the vcpu's vmcs01 is the current VMCS on the CPU that executes nested_release_vmcs12(). If this assumption is violated, the vcpu's vmcs01 may be made active on multiple CPUs at the same time, in violation of Intel's specification. Moreover, since the vcpu's vmcs01 is not VMCLEARed on every CPU on which it is active, it can linger in a CPU's VMCS cache after it has been freed and potentially repurposed. Subsequent eviction from the CPU's VMCS cache on a capacity miss can result in memory corruption. It is not sufficient for vmx_free_vcpu() to call vmx_load_vmcs01(). If the vcpu in question was last loaded on a different CPU, it must be migrated to the current CPU before calling vmx_load_vmcs01(). Signed-off-by: Jim Mattson <jmattson@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14kvm: vmx: ensure VMCS is current while enabling PMLPeter Feiner
Between loading the new VMCS and enabling PML, the CPU was unpinned. If the vCPU thread were migrated to another CPU in the interim (e.g., due to preemption or sleeping alloc_page), then the VMWRITEs to enable PML would target the wrong VMCS -- or no VMCS at all: [ 2087.266950] vmwrite error: reg 200e value 3fe1d52000 (err -506126336) [ 2087.267062] vmwrite error: reg 812 value 1ff (err 511) [ 2087.267125] vmwrite error: reg 401e value 12229c00 (err 304258048) This patch ensures that the VMCS remains current while enabling PML by doing the VMWRITEs while the CPU is pinned. Allocation of the PML buffer is hoisted out of the critical section. Signed-off-by: Peter Feiner <pfeiner@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14KVM: x86: add KVM_CAP_X2APIC_APIRadim Krčmář
KVM_CAP_X2APIC_API is a capability for features related to x2APIC enablement. KVM_X2APIC_API_32BIT_FORMAT feature can be enabled to extend APIC ID in get/set ioctl and MSI addresses to 32 bits. Both are needed to support x2APIC. The feature has to be enableable and disabled by default, because get/set ioctl shifted and truncated APIC ID to 8 bits by using a non-standard protocol inspired by xAPIC and the change is not backward-compatible. Changes to MSI addresses follow the format used by interrupt remapping unit. The upper address word, that used to be 0, contains upper 24 bits of the LAPIC address in its upper 24 bits. Lower 8 bits are reserved as 0. Using the upper address word is not backward-compatible either as we didn't check that userspace zeroed the word. Reserved bits are still not explicitly checked, but non-zero data will affect LAPIC addresses, which will cause a bug. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14KVM: VMX: optimize APIC ID read with APICvRadim Krčmář
The register is in hardware-compatible format now, so there is not need to intercept. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14kvm: vmx: advertise support for ept execute onlyBandan Das
MMU now knows about execute only mappings, so advertise the feature to L1 hypervisors Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14kvm: mmu: track read permission explicitly for shadow EPT page tablesBandan Das
To support execute only mappings on behalf of L1 hypervisors, reuse ACC_USER_MASK to signify if the L1 hypervisor has the R bit set. For the nested EPT case, we assumed that the U bit was always set since there was no equivalent in EPT page tables. Strictly speaking, this was not necessary because handle_ept_violation never set PFERR_USER_MASK in the error code (uf=0 in the parlance of update_permission_bitmask). We now have to set both U and UF correctly, respectively in FNAME(gpte_access) and in handle_ept_violation. Also in handle_ept_violation bit 3 of the exit qualification is not enough to detect a present PTE; all three bits 3-5 have to be checked. Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14kvm: mmu: don't set the present bit unconditionallyBandan Das
To support execute only mappings on behalf of L1 hypervisors, we need to teach set_spte() to honor all three of L1's XWR bits. As a start, add a new variable "shadow_present_mask" that will be set for non-EPT shadow paging and clear for EPT. Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-11KVM: VMX: introduce vm_{entry,exit}_control_reset_shadowPaolo Bonzini
There is no reason to read the entry/exit control fields of the VMCS and immediately write back the same value. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-11KVM: nVMX: keep preemption timer enabled during L2 executionPaolo Bonzini
Because the vmcs12 preemption timer is emulated through a separate hrtimer, we can keep on using the preemption timer in the vmcs02 to emulare L1's TSC deadline timer. However, the corresponding bit in the pin-based execution control field must be kept consistent between vmcs01 and vmcs02. On vmentry we copy it into the vmcs02; on vmexit the preemption timer must be disabled in the vmcs01 if a preemption timer vmexit happened while in guest mode. The preemption timer value in the vmcs02 is set by vmx_vcpu_run, so it need not be considered in prepare_vmcs02. Cc: Yunhong Jiang <yunhong.jiang@intel.com> Cc: Haozhong Zhang <haozhong.zhang@intel.com> Tested-by: Wanpeng Li <kernellwp@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-11KVM: nVMX: avoid incorrect preemption timer vmexit in nested guestWanpeng Li
The preemption timer for nested VMX is emulated by hrtimer which is started on L2 entry, stopped on L2 exit and evaluated via the check_nested_events hook. However, nested_vmx_exit_handled is always returning true for preemption timer vmexit. Then, the L1 preemption timer vmexit is captured and be treated as a L2 preemption timer vmexit, causing NULL pointer dereferences or worse in the L1 guest's vmexit handler: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 0 Oops: 0010 [#1] SMP Call Trace: ? kvm_lapic_expired_hv_timer+0x47/0x90 [kvm] handle_preemption_timer+0xe/0x20 [kvm_intel] vmx_handle_exit+0x169/0x15a0 [kvm_intel] ? kvm_arch_vcpu_ioctl_run+0xd5d/0x19d0 [kvm] kvm_arch_vcpu_ioctl_run+0xdee/0x19d0 [kvm] ? kvm_arch_vcpu_ioctl_run+0xd5d/0x19d0 [kvm] ? vcpu_load+0x1c/0x60 [kvm] ? kvm_arch_vcpu_load+0x57/0x260 [kvm] kvm_vcpu_ioctl+0x2d3/0x7c0 [kvm] do_vfs_ioctl+0x96/0x6a0 ? __fget_light+0x2a/0x90 SyS_ioctl+0x79/0x90 do_syscall_64+0x68/0x180 entry_SYSCALL64_slow_path+0x25/0x25 Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff8800b5263c48> CR2: 0000000000000000 ---[ end trace 9c70c48b1a2bc66e ]--- This can be reproduced readily by preemption timer enabled on L0 and disabled on L1. Return false since preemption timer vmexits must never be reflected to L2. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Yunhong Jiang <yunhong.jiang@intel.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-11KVM: VMX: reflect broken preemption timer in vmcs_configPaolo Bonzini
Simplify cpu_has_vmx_preemption_timer. This is consistent with the rest of setup_vmcs_config and preparatory for the next patch. Tested-by: Wanpeng Li <kernellwp@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-05KVM: x86: Use ARRAY_SIZE instead of dividing sizeof array with sizeof an elementWei Yongjun
Use ARRAY_SIZE instead of dividing sizeof array with sizeof an element Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-01KVM: vmx: fix underflow in TSC deadline calculationPaolo Bonzini
If the TSC deadline timer is programmed really close to the deadline or even in the past, the computation in vmx_set_hv_timer can underflow and cause delta_tsc to be set to a huge value. This generally results in vmx_set_hv_timer returning -ERANGE, but we can fix it by limiting delta_tsc to be positive or zero. Reported-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-01KVM: x86: use guest_exit_irqoffPaolo Bonzini
This gains a few clock cycles per vmexit. On Intel there is no need anymore to enable the interrupts in vmx_handle_external_intr, since we are using the "acknowledge interrupt on exit" feature. AMD needs to do that, and must be careful to avoid the interrupt shadow. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-01KVM: x86: always use "acknowledge interrupt on exit"Paolo Bonzini
This is necessary to simplify handle_external_intr in the next patch. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-27KVM: nVMX: VMX instructions: fix segment checks when L1 is in long mode.Quentin Casasnovas
I couldn't get Xen to boot a L2 HVM when it was nested under KVM - it was getting a GP(0) on a rather unspecial vmread from Xen: (XEN) ----[ Xen-4.7.0-rc x86_64 debug=n Not tainted ]---- (XEN) CPU: 1 (XEN) RIP: e008:[<ffff82d0801e629e>] vmx_get_segment_register+0x14e/0x450 (XEN) RFLAGS: 0000000000010202 CONTEXT: hypervisor (d1v0) (XEN) rax: ffff82d0801e6288 rbx: ffff83003ffbfb7c rcx: fffffffffffab928 (XEN) rdx: 0000000000000000 rsi: 0000000000000000 rdi: ffff83000bdd0000 (XEN) rbp: ffff83000bdd0000 rsp: ffff83003ffbfab0 r8: ffff830038813910 (XEN) r9: ffff83003faf3958 r10: 0000000a3b9f7640 r11: ffff83003f82d418 (XEN) r12: 0000000000000000 r13: ffff83003ffbffff r14: 0000000000004802 (XEN) r15: 0000000000000008 cr0: 0000000080050033 cr4: 00000000001526e0 (XEN) cr3: 000000003fc79000 cr2: 0000000000000000 (XEN) ds: 0000 es: 0000 fs: 0000 gs: 0000 ss: 0000 cs: e008 (XEN) Xen code around <ffff82d0801e629e> (vmx_get_segment_register+0x14e/0x450): (XEN) 00 00 41 be 02 48 00 00 <44> 0f 78 74 24 08 0f 86 38 56 00 00 b8 08 68 00 (XEN) Xen stack trace from rsp=ffff83003ffbfab0: ... (XEN) Xen call trace: (XEN) [<ffff82d0801e629e>] vmx_get_segment_register+0x14e/0x450 (XEN) [<ffff82d0801f3695>] get_page_from_gfn_p2m+0x165/0x300 (XEN) [<ffff82d0801bfe32>] hvmemul_get_seg_reg+0x52/0x60 (XEN) [<ffff82d0801bfe93>] hvm_emulate_prepare+0x53/0x70 (XEN) [<ffff82d0801ccacb>] handle_mmio+0x2b/0xd0 (XEN) [<ffff82d0801be591>] emulate.c#_hvm_emulate_one+0x111/0x2c0 (XEN) [<ffff82d0801cd6a4>] handle_hvm_io_completion+0x274/0x2a0 (XEN) [<ffff82d0801f334a>] __get_gfn_type_access+0xfa/0x270 (XEN) [<ffff82d08012f3bb>] timer.c#add_entry+0x4b/0xb0 (XEN) [<ffff82d08012f80c>] timer.c#remove_entry+0x7c/0x90 (XEN) [<ffff82d0801c8433>] hvm_do_resume+0x23/0x140 (XEN) [<ffff82d0801e4fe7>] vmx_do_resume+0xa7/0x140 (XEN) [<ffff82d080164aeb>] context_switch+0x13b/0xe40 (XEN) [<ffff82d080128e6e>] schedule.c#schedule+0x22e/0x570 (XEN) [<ffff82d08012c0cc>] softirq.c#__do_softirq+0x5c/0x90 (XEN) [<ffff82d0801602c5>] domain.c#idle_loop+0x25/0x50 (XEN) (XEN) (XEN) **************************************** (XEN) Panic on CPU 1: (XEN) GENERAL PROTECTION FAULT (XEN) [error_code=0000] (XEN) **************************************** Tracing my host KVM showed it was the one injecting the GP(0) when emulating the VMREAD and checking the destination segment permissions in get_vmx_mem_address(): 3) | vmx_handle_exit() { 3) | handle_vmread() { 3) | nested_vmx_check_permission() { 3) | vmx_get_segment() { 3) 0.074 us | vmx_read_guest_seg_base(); 3) 0.065 us | vmx_read_guest_seg_selector(); 3) 0.066 us | vmx_read_guest_seg_ar(); 3) 1.636 us | } 3) 0.058 us | vmx_get_rflags(); 3) 0.062 us | vmx_read_guest_seg_ar(); 3) 3.469 us | } 3) | vmx_get_cs_db_l_bits() { 3) 0.058 us | vmx_read_guest_seg_ar(); 3) 0.662 us | } 3) | get_vmx_mem_address() { 3) 0.068 us | vmx_cache_reg(); 3) | vmx_get_segment() { 3) 0.074 us | vmx_read_guest_seg_base(); 3) 0.068 us | vmx_read_guest_seg_selector(); 3) 0.071 us | vmx_read_guest_seg_ar(); 3) 1.756 us | } 3) | kvm_queue_exception_e() { 3) 0.066 us | kvm_multiple_exception(); 3) 0.684 us | } 3) 4.085 us | } 3) 9.833 us | } 3) + 10.366 us | } Cross-checking the KVM/VMX VMREAD emulation code with the Intel Software Developper Manual Volume 3C - "VMREAD - Read Field from Virtual-Machine Control Structure", I found that we're enforcing that the destination operand is NOT located in a read-only data segment or any code segment when the L1 is in long mode - BUT that check should only happen when it is in protected mode. Shuffling the code a bit to make our emulation follow the specification allows me to boot a Xen dom0 in a nested KVM and start HVM L2 guests without problems. Fixes: f9eb4af67c9d ("KVM: nVMX: VMX instructions: add checks for #GP/#SS exceptions") Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Eugene Korenevsky <ekorenevsky@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-23KVM: VMX: enable guest access to LMCE related MSRsAshok Raj
On Intel platforms, this patch adds LMCE to KVM MCE supported capabilities and handles guest access to LMCE related MSRs. Signed-off-by: Ashok Raj <ashok.raj@intel.com> [Haozhong: macro KVM_MCE_CAP_SUPPORTED => variable kvm_mce_cap_supported Only enable LMCE on Intel platform Check MSR_IA32_FEATURE_CONTROL when handling guest access to MSR_IA32_MCG_EXT_CTL] Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-23KVM: VMX: validate individual bits of guest MSR_IA32_FEATURE_CONTROLHaozhong Zhang
KVM currently does not check the value written to guest MSR_IA32_FEATURE_CONTROL, though bits corresponding to disabled features may be set. This patch makes KVM to validate individual bits written to guest MSR_IA32_FEATURE_CONTROL according to enabled features. Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-23KVM: VMX: move msr_ia32_feature_control to vcpu_vmxHaozhong Zhang
msr_ia32_feature_control will be used for LMCE and not depend only on nested anymore, so move it from struct nested_vmx to struct vcpu_vmx. Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16kvm: vmx: hook preemption timer supportYunhong Jiang
Hook the VMX preemption timer to the "hv timer" functionality added by the previous patch. This includes: checking if the feature is supported, if the feature is broken on the CPU, the hooks to setup/clean the VMX preemption timer, arming the timer on vmentry and handling the vmexit. A module parameter states if the VMX preemption timer should be utilized. Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com> [Move hv_deadline_tsc to struct vcpu_vmx, use -1 as the "unset" value. Put all VMX bits here. Enable it by default #yolo. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16kvm: vmx: rename vmx_pre/post_block to pi_pre/post_blockYunhong Jiang
Prepare to switch from preemption timer to hrtimer in the vmx_pre/post_block. Current functions are only for posted interrupt, rename them accordingly. Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16kvm: vmx: check apicv is active before using VT-d posted interruptYang Zhang
VT-d posted interrupt is relying on the CPU side's posted interrupt. Need to check whether VCPU's APICv is active before enabing VT-d posted interrupt. Fixes: d62caabb41f33d96333f9ef15e09cd26e1c12760 Cc: stable@vger.kernel.org Signed-off-by: Yang Zhang <yang.zhang.wz@gmail.com> Signed-off-by: Shengge Ding <shengge.dsg@alibaba-inc.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14KVM: x86: Fix typosAndrea Gelmini
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-27Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull second batch of KVM updates from Radim Krčmář: "General: - move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat (kvm_stat had nothing to do with QEMU in the first place -- the tool only interprets debugfs) - expose per-vm statistics in debugfs and support them in kvm_stat (KVM always collected per-vm statistics, but they were summarised into global statistics) x86: - fix dynamic APICv (VMX was improperly configured and a guest could access host's APIC MSRs, CVE-2016-4440) - minor fixes ARM changes from Christoffer Dall: - new vgic reimplementation of our horribly broken legacy vgic implementation. The two implementations will live side-by-side (with the new being the configured default) for one kernel release and then we'll remove the legacy one. - fix for a non-critical issue with virtual abort injection to guests" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (70 commits) tools: kvm_stat: Add comments tools: kvm_stat: Introduce pid monitoring KVM: Create debugfs dir and stat files for each VM MAINTAINERS: Add kvm tools tools: kvm_stat: Powerpc related fixes tools: Add kvm_stat man page tools: Add kvm_stat vm monitor script kvm:vmx: more complete state update on APICv on/off KVM: SVM: Add more SVM_EXIT_REASONS KVM: Unify traced vector format svm: bitwise vs logical op typo KVM: arm/arm64: vgic-new: Synchronize changes to active state KVM: arm/arm64: vgic-new: enable build KVM: arm/arm64: vgic-new: implement mapped IRQ handling KVM: arm/arm64: vgic-new: Wire up irqfd injection KVM: arm/arm64: vgic-new: Add vgic_v2/v3_enable KVM: arm/arm64: vgic-new: vgic_init: implement map_resources KVM: arm/arm64: vgic-new: vgic_init: implement vgic_init KVM: arm/arm64: vgic-new: vgic_init: implement vgic_create KVM: arm/arm64: vgic-new: vgic_init: implement kvm_vgic_hyp_init ...
2016-05-25kvm:vmx: more complete state update on APICv on/offRoman Kagan
The function to update APICv on/off state (in particular, to deactivate it when enabling Hyper-V SynIC) is incomplete: it doesn't adjust APICv-related fields among secondary processor-based VM-execution controls. As a result, Windows 2012 guests get stuck when SynIC-based auto-EOI interrupt intersected with e.g. an IPI in the guest. In addition, the MSR intercept bitmap isn't updated every time "virtualize x2APIC mode" is toggled. This path can only be triggered by a malicious guest, because Windows didn't use x2APIC but rather their own synthetic APIC access MSRs; however a guest running in a SynIC-enabled VM could switch to x2APIC and thus obtain direct access to host APIC MSRs (CVE-2016-4440). The patch fixes those omissions. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> Reported-by: Steve Rutherford <srutherford@google.com> Reported-by: Yang Zhang <yang.zhang.wz@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-19Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "Small release overall. x86: - miscellaneous fixes - AVIC support (local APIC virtualization, AMD version) s390: - polling for interrupts after a VCPU goes to halted state is now enabled for s390 - use hardware provided information about facility bits that do not need any hypervisor activity, and other fixes for cpu models and facilities - improve perf output - floating interrupt controller improvements. MIPS: - miscellaneous fixes PPC: - bugfixes only ARM: - 16K page size support - generic firmware probing layer for timer and GIC Christoffer Dall (KVM-ARM maintainer) says: "There are a few changes in this pull request touching things outside KVM, but they should all carry the necessary acks and it made the merge process much easier to do it this way." though actually the irqchip maintainers' acks didn't make it into the patches. Marc Zyngier, who is both irqchip and KVM-ARM maintainer, later acked at http://mid.gmane.org/573351D1.4060303@arm.com ('more formally and for documentation purposes')" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (82 commits) KVM: MTRR: remove MSR 0x2f8 KVM: x86: make hwapic_isr_update and hwapic_irr_update look the same svm: Manage vcpu load/unload when enable AVIC svm: Do not intercept CR8 when enable AVIC svm: Do not expose x2APIC when enable AVIC KVM: x86: Introducing kvm_x86_ops.apicv_post_state_restore svm: Add VMEXIT handlers for AVIC svm: Add interrupt injection via AVIC KVM: x86: Detect and Initialize AVIC support svm: Introduce new AVIC VMCB registers KVM: split kvm_vcpu_wake_up from kvm_vcpu_kick KVM: x86: Introducing kvm_x86_ops VCPU blocking/unblocking hooks KVM: x86: Introducing kvm_x86_ops VM init/destroy hooks KVM: x86: Rename kvm_apic_get_reg to kvm_lapic_get_reg KVM: x86: Misc LAPIC changes to expose helper functions KVM: shrink halt polling even more for invalid wakeups KVM: s390: set halt polling to 80 microseconds KVM: halt_polling: provide a way to qualify wakeups during poll KVM: PPC: Book3S HV: Re-enable XICS fast path for irqfd-generated interrupts kvm: Conditionally register IRQ bypass consumer ...
2016-05-18KVM: x86: make hwapic_isr_update and hwapic_irr_update look the samePaolo Bonzini
Neither APICv nor AVIC actually need the first argument of hwapic_isr_update, but the vCPU makes more sense than passing the pointer to the whole virtual machine! In fact in the APICv case it's just happening that the vCPU is used implicitly, through the loaded VMCS. The second argument instead is named differently, make it consistent. Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-05Merge tag 'v4.6-rc6' into x86/asm, to refresh the treeIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-29KVM: x86: fix ordering of cr0 initialization code in vmx_cpu_resetBruce Rogers
Commit d28bc9dd25ce reversed the order of two lines which initialize cr0, allowing the current (old) cr0 value to mess up vcpu initialization. This was observed in the checks for cr0 X86_CR0_WP bit in the context of kvm_mmu_reset_context(). Besides, setting vcpu->arch.cr0 after vmx_set_cr0() is completely redundant. Change the order back to ensure proper vcpu initialization. The combination of booting with ovmf firmware when guest vcpus > 1 and kvm's ept=N option being set results in a VM-entry failure. This patch fixes that. Fixes: d28bc9dd25ce ("KVM: x86: INIT and reset sequences are different") Cc: stable@vger.kernel.org Signed-off-by: Bruce Rogers <brogers@suse.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-04-28perf/x86/intel/pt: Don't die on VMXONAlexander Shishkin
Some versions of Intel PT do not support tracing across VMXON, more specifically, VMXON will clear TraceEn control bit and any attempt to set it before VMXOFF will throw a #GP, which in the current state of things will crash the kernel. Namely: $ perf record -e intel_pt// kvm -nographic on such a machine will kill it. To avoid this, notify the intel_pt driver before VMXON and after VMXOFF so that it knows when not to enable itself. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Gleb Natapov <gleb@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: hpa@zytor.com Link: http://lkml.kernel.org/r/87oa9dwrfk.fsf@ashishki-desk.ger.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13x86/cpufeature: Replace cpu_has_xsaves with boot_cpu_has() usageBorislav Petkov
Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <kvm@vger.kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459801503-15600-11-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-24Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes: - fix hotplug bugs - fix irq live lock - fix various topology handling bugs - fix APIC ACK ordering - fix PV iopl handling - fix speling - fix/tweak memcpy_mcsafe() return value - fix fbcon bug - remove stray prototypes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/msr: Remove unused native_read_tscp() x86/apic: Remove declaration of unused hw_nmi_is_cpu_stuck x86/oprofile/nmi: Add missing hotplug FROZEN handling x86/hpet: Use proper mask to modify hotplug action x86/apic/uv: Fix the hotplug notifier x86/apb/timer: Use proper mask to modify hotplug action x86/topology: Use total_cpus not nr_cpu_ids for logical packages x86/topology: Fix Intel HT disable x86/topology: Fix logical package mapping x86/irq: Cure live lock in fixup_irqs() x86/tsc: Prevent NULL pointer deref in calibrate_delay_is_known() x86/apic: Fix suspicious RCU usage in smp_trace_call_function_interrupt() x86/iopl: Fix iopl capability check on Xen PV x86/iopl/64: Properly context-switch IOPL on Xen PV selftests/x86: Add an iopl test x86/mm, x86/mce: Fix return type/value for memcpy_mcsafe() x86/video: Don't assume all FB devices are PCI devices arch/x86/irq: Purge useless handler declarations from hw_irq.h x86: Fix misspellings in comments
2016-03-22KVM, pkeys: add pkeys support for permission_faultHuaitong Han
Protection keys define a new 4-bit protection key field (PKEY) in bits 62:59 of leaf entries of the page tables, the PKEY is an index to PKRU register(16 domains), every domain has 2 bits(write disable bit, access disable bit). Static logic has been produced in update_pkru_bitmask, dynamic logic need read pkey from page table entries, get pkru value, and deduce the correct result. [ Huaitong: Xiao helps to modify many sections. ] Signed-off-by: Huaitong Han <huaitong.han@intel.com> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22KVM, pkeys: save/restore PKRU when guest/host switchesXiao Guangrong
Currently XSAVE state of host is not restored after VM-exit and PKRU is managed by XSAVE so the PKRU from guest is still controlling the memory access even if the CPU is running the code of host. This is not safe as KVM needs to access the memory of userspace (e,g QEMU) to do some emulation. So we save/restore PKRU when guest/host switches. Signed-off-by: Huaitong Han <huaitong.han@intel.com> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22KVM, pkeys: disable pkeys for guests in non-paging modeHuaitong Han
Pkeys is disabled if CPU is in non-paging mode in hardware. However KVM always uses paging mode to emulate guest non-paging, mode with TDP. To emulate this behavior, pkeys needs to be manually disabled when guest switches to non-paging mode. Signed-off-by: Huaitong Han <huaitong.han@intel.com> Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22KVM: VMX: fix nested vpid for old KVM guestsPaolo Bonzini
Old KVM guests invoke single-context invvpid without actually checking whether it is supported. This was fixed by commit 518c8ae ("KVM: VMX: Make sure single type invvpid is supported before issuing invvpid instruction", 2010-08-01) and the patch after, but pre-2.6.36 kernels lack it including RHEL 6. Reported-by: jmontleo@redhat.com Tested-by: jmontleo@redhat.com Cc: stable@vger.kernel.org Fixes: 99b83ac893b84ed1a62ad6d1f2b6cc32026b9e85 Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22KVM: VMX: avoid guest hang on invalid invvpid instructionPaolo Bonzini
A guest executing an invalid invvpid instruction would hang because the instruction pointer was not updated. Reported-by: jmontleo@redhat.com Tested-by: jmontleo@redhat.com Cc: stable@vger.kernel.org Fixes: 99b83ac893b84ed1a62ad6d1f2b6cc32026b9e85 Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22KVM: VMX: avoid guest hang on invalid invept instructionPaolo Bonzini
A guest executing an invalid invept instruction would hang because the instruction pointer was not updated. Cc: stable@vger.kernel.org Fixes: bfd0a56b90005f8c8a004baf407ad90045c2b11e Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>