lkml.org 
[lkml]   [2021]   [Sep]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/2] KVM: X86: Don't reset mmu context when toggling X86_CR4_PGE
Date
From: Lai Jiangshan <laijs@linux.alibaba.com>

X86_CR4_PGE doesn't participate in kvm_mmu_role, so the mmu context
doesn't need to be reset. It is only required to flush all the guest
tlb.

It is also inconsistent that X86_CR4_PGE is in KVM_MMU_CR4_ROLE_BITS
while kvm_mmu_role doesn't use X86_CR4_PGE. So X86_CR4_PGE is also
removed from KVM_MMU_CR4_ROLE_BITS.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
---
arch/x86/kvm/mmu.h | 5 ++---
arch/x86/kvm/x86.c | 3 ++-
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 75367af1a6d3..e53ef2ae958f 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -44,9 +44,8 @@
#define PT32_ROOT_LEVEL 2
#define PT32E_ROOT_LEVEL 3

-#define KVM_MMU_CR4_ROLE_BITS (X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE | \
- X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE | \
- X86_CR4_LA57)
+#define KVM_MMU_CR4_ROLE_BITS (X86_CR4_PSE | X86_CR4_PAE | X86_CR4_LA57 | \
+ X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE)

#define KVM_MMU_CR0_ROLE_BITS (X86_CR0_PG | X86_CR0_WP)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7494ea0e7922..97772e37e8ee 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1045,7 +1045,8 @@ void kvm_post_set_cr4(struct kvm_vcpu *vcpu, unsigned long old_cr4, unsigned lon
{
if ((cr4 ^ old_cr4) & KVM_MMU_CR4_ROLE_BITS)
kvm_mmu_reset_context(vcpu);
- else if (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE))
+ else if (((cr4 ^ old_cr4) & X86_CR4_PGE) ||
+ (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE)))
kvm_vcpu_flush_tlb_guest(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_post_set_cr4);
--
2.19.1.6.gb485710b
\
 
 \ /
  Last update: 2021-09-19 04:43    [W:0.081 / U:0.404 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site