Messages in this thread | | | Date | Thu, 18 Nov 2021 17:05:47 +0100 | Subject | Re: [PATCH 01/15] KVM: VMX: Use x86 core API to access to fs_base and inactive gs_base | From | Paolo Bonzini <> |
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On 11/18/21 12:08, Lai Jiangshan wrote: > From: Lai Jiangshan <laijs@linux.alibaba.com> > > And they use FSGSBASE instructions when enabled. > > Cc: x86@kernel.org > Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
This needs ACK from x86 maintainers.
I queued 2-4 and 6-14.
Paolo
> --- > arch/x86/include/asm/kvm_host.h | 10 ---------- > arch/x86/kernel/process_64.c | 2 ++ > arch/x86/kvm/vmx/vmx.c | 14 +++++++------- > 3 files changed, 9 insertions(+), 17 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 1fcb345bc107..4cbb402f5636 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1808,16 +1808,6 @@ static inline void kvm_load_ldt(u16 sel) > asm("lldt %0" : : "rm"(sel)); > } > > -#ifdef CONFIG_X86_64 > -static inline unsigned long read_msr(unsigned long msr) > -{ > - u64 value; > - > - rdmsrl(msr, value); > - return value; > -} > -#endif > - > static inline void kvm_inject_gp(struct kvm_vcpu *vcpu, u32 error_code) > { > kvm_queue_exception_e(vcpu, GP_VECTOR, error_code); > diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c > index 3402edec236c..296bd5c2e38b 100644 > --- a/arch/x86/kernel/process_64.c > +++ b/arch/x86/kernel/process_64.c > @@ -443,6 +443,7 @@ unsigned long x86_gsbase_read_cpu_inactive(void) > > return gsbase; > } > +EXPORT_SYMBOL_GPL(x86_gsbase_read_cpu_inactive); > > void x86_gsbase_write_cpu_inactive(unsigned long gsbase) > { > @@ -456,6 +457,7 @@ void x86_gsbase_write_cpu_inactive(unsigned long gsbase) > wrmsrl(MSR_KERNEL_GS_BASE, gsbase); > } > } > +EXPORT_SYMBOL_GPL(x86_gsbase_write_cpu_inactive); > > unsigned long x86_fsbase_read_task(struct task_struct *task) > { > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 3127c66a1651..48a34d1a2989 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -1156,11 +1156,11 @@ void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) > } else { > savesegment(fs, fs_sel); > savesegment(gs, gs_sel); > - fs_base = read_msr(MSR_FS_BASE); > - vmx->msr_host_kernel_gs_base = read_msr(MSR_KERNEL_GS_BASE); > + fs_base = x86_fsbase_read_cpu(); > + vmx->msr_host_kernel_gs_base = x86_gsbase_read_cpu_inactive(); > } > > - wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base); > + x86_gsbase_write_cpu_inactive(vmx->msr_guest_kernel_gs_base); > #else > savesegment(fs, fs_sel); > savesegment(gs, gs_sel); > @@ -1184,7 +1184,7 @@ static void vmx_prepare_switch_to_host(struct vcpu_vmx *vmx) > ++vmx->vcpu.stat.host_state_reload; > > #ifdef CONFIG_X86_64 > - rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base); > + vmx->msr_guest_kernel_gs_base = x86_gsbase_read_cpu_inactive(); > #endif > if (host_state->ldt_sel || (host_state->gs_sel & 7)) { > kvm_load_ldt(host_state->ldt_sel); > @@ -1204,7 +1204,7 @@ static void vmx_prepare_switch_to_host(struct vcpu_vmx *vmx) > #endif > invalidate_tss_limit(); > #ifdef CONFIG_X86_64 > - wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base); > + x86_gsbase_write_cpu_inactive(vmx->msr_host_kernel_gs_base); > #endif > load_fixmap_gdt(raw_smp_processor_id()); > vmx->guest_state_loaded = false; > @@ -1216,7 +1216,7 @@ static u64 vmx_read_guest_kernel_gs_base(struct vcpu_vmx *vmx) > { > preempt_disable(); > if (vmx->guest_state_loaded) > - rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base); > + vmx->msr_guest_kernel_gs_base = x86_gsbase_read_cpu_inactive(); > preempt_enable(); > return vmx->msr_guest_kernel_gs_base; > } > @@ -1225,7 +1225,7 @@ static void vmx_write_guest_kernel_gs_base(struct vcpu_vmx *vmx, u64 data) > { > preempt_disable(); > if (vmx->guest_state_loaded) > - wrmsrl(MSR_KERNEL_GS_BASE, data); > + x86_gsbase_write_cpu_inactive(data); > preempt_enable(); > vmx->msr_guest_kernel_gs_base = data; > } >
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