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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2018-03-13 20:48:05 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-03-17 00:03:54 +0300 |
| commit | 35060ed6a1ffc92106904f5e4b5823ca4facfc73 (patch) | |
| tree | 8bb681a4e0b7c15fd173e0c27aba1bd2460856ec /arch/x86/include/asm/processor.h | |
| parent | 42b933b59721f288e3ce23ca79a17a973808dab9 (diff) | |
| download | linux-35060ed6a1ffc92106904f5e4b5823ca4facfc73.tar.xz | |
x86/kvm/vmx: avoid expensive rdmsr for MSR_GS_BASE
vmx_save_host_state() is only called from kvm_arch_vcpu_ioctl_run() so
the context is pretty well defined and as we're past 'swapgs' MSR_GS_BASE
should contain kernel's GS base which we point to irq_stack_union.
Add new kernelmode_gs_base() API, irq_stack_union needs to be exported
as KVM can be build as module.
Acked-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm/processor.h')
| -rw-r--r-- | arch/x86/include/asm/processor.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 1d816a3325a1..4fa4206029e3 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -407,6 +407,11 @@ union irq_stack_union { DECLARE_PER_CPU_FIRST(union irq_stack_union, irq_stack_union) __visible; DECLARE_INIT_PER_CPU(irq_stack_union); +static inline unsigned long cpu_kernelmode_gs_base(int cpu) +{ + return (unsigned long)per_cpu(irq_stack_union.gs_base, cpu); +} + DECLARE_PER_CPU(char *, irq_stack_ptr); DECLARE_PER_CPU(unsigned int, irq_count); extern asmlinkage void ignore_sysret(void); |