[PATCH 04/15] KVM: VMX: Add and use X86_CR4_TLB_BITS when !enable_ept

Lai Jiangshan
2021-11-08T12:44:34Z

From: Lai Jiangshan <laijs@linux.alibaba.com>

In set_cr4_guest_host_mask(), X86_CR4_PGE is set to be intercepted when
!enable_ept just because X86_CR4_PGE is the only bit that is
responsible for flushing TLB but listed in KVM_POSSIBLE_CR4_GUEST_BITS.

It is clearer and self-documented to use X86_CR4_TLB_BITS instead.

No functionality changed.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
---
arch/x86/kvm/kvm_cache_regs.h | 2 ++
arch/x86/kvm/vmx/vmx.c | 2 +-
2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index 90e1ffdc05b7..8fe036efa654 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -9,6 +9,8 @@
(X86_CR4_PVI | X86_CR4_DE | X86_CR4_PCE | X86_CR4_OSFXSR \
| X86_CR4_OSXMMEXCPT | X86_CR4_PGE | X86_CR4_TSD | X86_CR4_FSGSBASE)

+#define X86_CR4_TLB_BITS (X86_CR4_PGE | X86_CR4_PCIDE | X86_CR4_PAE | X86_CR4_SMEP)
+
#define BUILD_KVM_GPR_ACCESSORS(lname, uname) \
static __always_inline unsigned long kvm_##lname##_read(struct kvm_vcpu *vcpu)\
{ \
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 79e5df5fbb32..1795702dc6de 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4107,7 +4107,7 @@ void set_cr4_guest_host_mask(struct vcpu_vmx *vmx)
vcpu->arch.cr4_guest_owned_bits = KVM_POSSIBLE_CR4_GUEST_BITS &
~vcpu->arch.cr4_guest_rsvd_bits;
if (!enable_ept)
- vcpu->arch.cr4_guest_owned_bits &= ~X86_CR4_PGE;
+ vcpu->arch.cr4_guest_owned_bits &= ~X86_CR4_TLB_BITS;
if (is_guest_mode(&vmx->vcpu))
vcpu->arch.cr4_guest_owned_bits &=
~get_vmcs12(vcpu)->cr4_guest_host_mask;
--
2.19.1.6.gb485710b