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author | James Hogan <james.hogan@imgtec.com> | 2016-06-09 13:19:14 (GMT) |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-06-14 09:02:44 (GMT) |
commit | 878edf014e29de38c49153aba20273fbc9ae31af (patch) | |
tree | 0ea5871f8a035389da5aa423e72a0a58f2033473 /arch/mips/kernel | |
parent | 26ee17ff71d3def831bfa4f6851ed1ba789e24f6 (diff) | |
download | linux-878edf014e29de38c49153aba20273fbc9ae31af.tar.xz |
MIPS: KVM: Restore host EBase from ebase variable
The host kernel's exception vector base address is currently saved in
the VCPU structure at creation time, and restored on a guest exit.
However it doesn't change and can already be easily accessed from the
'ebase' variable (arch/mips/kernel/traps.c), so drop the host_ebase
member of kvm_vcpu_arch, export the 'ebase' variable to modules and load
from there instead.
This does result in a single extra instruction (lui) on the guest exit
path, but simplifies the code a bit and removes the redundant storage of
the host exception base address.
Credit for the idea goes to Cavium's VZ KVM implementation.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/mips/kernel')
-rw-r--r-- | arch/mips/kernel/asm-offsets.c | 1 | ||||
-rw-r--r-- | arch/mips/kernel/traps.c | 1 |
2 files changed, 1 insertions, 1 deletions
diff --git a/arch/mips/kernel/asm-offsets.c b/arch/mips/kernel/asm-offsets.c index 4208088..a1263d1 100644 --- a/arch/mips/kernel/asm-offsets.c +++ b/arch/mips/kernel/asm-offsets.c @@ -355,7 +355,6 @@ void output_kvm_defines(void) OFFSET(VCPU_RUN, kvm_vcpu, run); OFFSET(VCPU_HOST_ARCH, kvm_vcpu, arch); - OFFSET(VCPU_HOST_EBASE, kvm_vcpu_arch, host_ebase); OFFSET(VCPU_GUEST_EBASE, kvm_vcpu_arch, guest_ebase); OFFSET(VCPU_HOST_STACK, kvm_vcpu_arch, host_stack); diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 4a1712b..66e5820 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -1859,6 +1859,7 @@ void __noreturn nmi_exception_handler(struct pt_regs *regs) #define VECTORSPACING 0x100 /* for EI/VI mode */ unsigned long ebase; +EXPORT_SYMBOL_GPL(ebase); unsigned long exception_handlers[32]; unsigned long vi_handlers[64]; |