Vitaly Kuznetsov <[email protected]> writes: > Alternative patch: remove the filtering from kvm_mmu_get_page() and check > for direct on call sites. cr4_pae setting in kvm_calc_mmu_role_common() > can be preserved for consistency. > > Signed-off-by: Vitaly Kuznetsov <[email protected]> > --- > arch/x86/kvm/mmu.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index f2d1d230d5b8..7fb8118f2af6 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -2420,8 +2420,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct > kvm_vcpu *vcpu, > role = vcpu->arch.mmu->mmu_role.base; > role.level = level; > role.direct = direct; > - if (role.direct) > - role.cr4_pae = 0; > role.access = access; > if (!vcpu->arch.mmu->direct_map > && vcpu->arch.mmu->root_level <= PT32_ROOT_LEVEL) { > @@ -5176,7 +5174,7 @@ static bool detect_write_misaligned(struct kvm_mmu_page > *sp, gpa_t gpa, > gpa, bytes, sp->role.word); > > offset = offset_in_page(gpa); > - pte_size = sp->role.cr4_pae ? 8 : 4; > + pte_size = (sp->role.cr4_pae && !sp->role.direct) ? 8 : 4; > > /* > * Sometimes, the OS only writes the last one bytes to update status > @@ -5200,7 +5198,7 @@ static u64 *get_written_sptes(struct kvm_mmu_page *sp, > gpa_t gpa, int *nspte) > page_offset = offset_in_page(gpa); > level = sp->role.level; > *nspte = 1; > - if (!sp->role.cr4_pae) { > + if (!sp->role.cr4_pae || sp->role.direct) { > page_offset <<= 1; /* 32->64 */ > /* > * A 32-bit pde maps 4MB while the shadow pdes map
While I personally prefer this approach to not setting role.cr4_pae in kvm_calc_mmu_role_common() I'd like to get maintainers opinion (I did test the patch with ept=off but I have to admit I don't know much about shadow page tables which actually use detect_write_misaligned()/ get_written_sptes()) Paolo, Radim, (anyone else) - any thoughts? -- Vitaly
