| Message ID | 1467088360-10186-3-git-send-email-bsd@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/28/2016 12:32 PM, Bandan Das wrote: > In reset_tdp_shadow_zero_bits_mask, we always pass false > when initializing the reserved bits. By initializing with the > correct value of ept exec only, the host can correctly > identify if the guest pte is valid. Note that > kvm_init_shadow_ept_mmu() already knows about execonly. > > Signed-off-by: Bandan Das <bsd@redhat.com> > --- > arch/x86/kvm/mmu.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index a50af79..875d4f7 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -3831,23 +3831,27 @@ static inline bool boot_cpu_is_amd(void) > > /* > * the direct page table on host, use as much mmu features as > - * possible, however, kvm currently does not do execution-protection. > + * possible > */ > static void > reset_tdp_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, > struct kvm_mmu *context) > { It is not necessary. reset_tdp_shadow_zero_bits_mask() is used for the guest without nested-ept, host never sets shadow execute-only actively. For the nested ept guest, kvm_init_shadow_ept_mmu() has already handled xonly case perfectly. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index a50af79..875d4f7 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3831,23 +3831,27 @@ static inline bool boot_cpu_is_amd(void) /* * the direct page table on host, use as much mmu features as - * possible, however, kvm currently does not do execution-protection. + * possible */ static void reset_tdp_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context) { + bool execonly; + if (boot_cpu_is_amd()) __reset_rsvds_bits_mask(vcpu, &context->shadow_zero_check, boot_cpu_data.x86_phys_bits, context->shadow_root_level, false, boot_cpu_has(X86_FEATURE_GBPAGES), true, true); - else + else { + execonly = !(context->guest_rsvd_check.bad_mt_xwr & + (1ull << VMX_EPT_EXECUTABLE_MASK)); __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, boot_cpu_data.x86_phys_bits, - false); - + execonly); + } } /*
In reset_tdp_shadow_zero_bits_mask, we always pass false when initializing the reserved bits. By initializing with the correct value of ept exec only, the host can correctly identify if the guest pte is valid. Note that kvm_init_shadow_ept_mmu() already knows about execonly. Signed-off-by: Bandan Das <bsd@redhat.com> --- arch/x86/kvm/mmu.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)