On Tue, Mar 08, 2011 at 03:57:40PM +0200, Avi Kivity wrote:
> We may read the cpl quite often in the same vmexit (instruction privilege
> check, memory access checks for instruction and operands), so we gain
> a bit if we cache the value.
>
Shouldn't VCPU_EXREG_CPL be cleared in vmx_set_efer too?
> Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
> ---
> arch/x86/include/asm/kvm_host.h | 1 +
> arch/x86/kvm/vmx.c | 17 ++++++++++++++++-
> 2 files changed, 17 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 80f3070..4a2496d 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -119,6 +119,7 @@ enum kvm_reg_ex {
> VCPU_EXREG_PDPTR = NR_VCPU_REGS,
> VCPU_EXREG_CR3,
> VCPU_EXREG_RFLAGS,
> + VCPU_EXREG_CPL,
> };
>
> enum {
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 82dbebd..87e3d86 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -128,6 +128,7 @@ struct vcpu_vmx {
> unsigned long host_rsp;
> int launched;
> u8 fail;
> + u8 cpl;
> u32 exit_intr_info;
> u32 idt_vectoring_info;
> ulong rflags;
> @@ -986,6 +987,7 @@ static unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu)
> static void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
> {
> __set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail);
> + __clear_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail);
> to_vmx(vcpu)->rflags = rflags;
> if (to_vmx(vcpu)->rmode.vm86_active) {
> to_vmx(vcpu)->rmode.save_rflags = rflags;
> @@ -1992,6 +1994,7 @@ static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
> vmcs_writel(CR0_READ_SHADOW, cr0);
> vmcs_writel(GUEST_CR0, hw_cr0);
> vcpu->arch.cr0 = cr0;
> + __clear_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail);
> }
>
> static u64 construct_eptp(unsigned long root_hpa)
> @@ -2102,7 +2105,7 @@ static u64 vmx_get_segment_base(struct kvm_vcpu *vcpu, int seg)
> return vmcs_readl(sf->base);
> }
>
> -static int vmx_get_cpl(struct kvm_vcpu *vcpu)
> +static int __vmx_get_cpl(struct kvm_vcpu *vcpu)
> {
> if (!is_protmode(vcpu))
> return 0;
> @@ -2114,6 +2117,16 @@ static int vmx_get_cpl(struct kvm_vcpu *vcpu)
> return vmcs_read16(GUEST_CS_SELECTOR) & 3;
> }
>
> +static int vmx_get_cpl(struct kvm_vcpu *vcpu)
> +{
> + if (!test_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail)) {
> + __set_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail);
> + to_vmx(vcpu)->cpl = __vmx_get_cpl(vcpu);
> + }
> + return to_vmx(vcpu)->cpl;
> +}
> +
> +
> static u32 vmx_segment_access_rights(struct kvm_segment *var)
> {
> u32 ar;
> @@ -2179,6 +2192,7 @@ static void vmx_set_segment(struct kvm_vcpu *vcpu,
> ar |= 0x1; /* Accessed */
>
> vmcs_write32(sf->ar_bytes, ar);
> + __clear_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail);
> }
>
> static void vmx_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)
> @@ -4116,6 +4130,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
>
> vcpu->arch.regs_avail = ~((1 << VCPU_REGS_RIP) | (1 << VCPU_REGS_RSP)
> | (1 << VCPU_EXREG_RFLAGS)
> + | (1 << VCPU_EXREG_CPL)
> | (1 << VCPU_EXREG_PDPTR)
> | (1 << VCPU_EXREG_CR3));
> vcpu->arch.regs_dirty = 0;
> --
> 1.7.1
--
Gleb.
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