On 11/18/21 12:08, Lai Jiangshan wrote:
From: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
When direct map, gpte_is_8_bytes has no meaning, but it is true for all
other cases except direct map when nonpaping.
Setting gpte_is_8_bytes to true when nonpaping can ensure that
!gpte_is_8_bytes means 32-bit gptes for shadow paging.
Then the right thing to do would be to rename it to has_4_byte_gptes and
invert the direction. But as things stand, it's a bit more confusing to
make gpte_is_8_bytes=1 if there are no guest PTEs at all.
Paolo
Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
---
Documentation/virt/kvm/mmu.rst | 2 +-
arch/x86/kvm/mmu/mmu.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/Documentation/virt/kvm/mmu.rst b/Documentation/virt/kvm/mmu.rst
index f60f5488e121..5d1086602759 100644
--- a/Documentation/virt/kvm/mmu.rst
+++ b/Documentation/virt/kvm/mmu.rst
@@ -179,7 +179,7 @@ Shadow pages contain the following information:
unpinned it will be destroyed.
role.gpte_is_8_bytes:
Reflects the size of the guest PTE for which the page is valid, i.e. '1'
- if 64-bit gptes are in use, '0' if 32-bit gptes are in use.
+ if direct map or 64-bit gptes are in use, '0' if 32-bit gptes are in use.
role.efer_nx:
Contains the value of efer.nx for which the page is valid.
role.cr0_wp:
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 6948f2d696c3..0c92cbc07320 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2083,7 +2083,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
role.level = level;
role.direct = direct;
role.access = access;
- if (!direct_mmu && !role.gpte_is_8_bytes) {
+ if (!role.gpte_is_8_bytes) {
quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
role.quadrant = quadrant;
@@ -4777,7 +4777,7 @@ kvm_calc_shadow_root_page_role_common(struct kvm_vcpu *vcpu,
role.base.smep_andnot_wp = role.ext.cr4_smep && !____is_cr0_wp(regs);
role.base.smap_andnot_wp = role.ext.cr4_smap && !____is_cr0_wp(regs);
- role.base.gpte_is_8_bytes = ____is_cr0_pg(regs) && ____is_cr4_pae(regs);
+ role.base.gpte_is_8_bytes = !____is_cr0_pg(regs) || ____is_cr4_pae(regs);
return role;
}
