From 0699c64a4be6e4a6137240379a1f82c752e663d8 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Tue, 30 Apr 2019 19:33:26 +0200 Subject: [PATCH] x86/kvm/mmu: reset MMU context when 32-bit guest switches PAE Commit 47c42e6b4192 ("KVM: x86: fix handling of role.cr4_pae and rename it to 'gpte_size'") introduced a regression: 32-bit PAE guests stopped working. The issue appears to be: when guest switches (enables) PAE we need to re-initialize MMU context (set context->root_level, do reset_rsvds_bits_mask(), ...) but init_kvm_tdp_mmu() doesn't do that because we threw away is_pae(vcpu) flag from mmu role. Restore it to kvm_mmu_extended_role (as we now don't need it in base role) to fix the issue. Fixes: 47c42e6b4192 ("KVM: x86: fix handling of role.cr4_pae and rename it to 'gpte_size'") Signed-off-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/mmu.c | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a9d03af34030..c79abe7ca093 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -295,6 +295,7 @@ union kvm_mmu_extended_role { unsigned int valid:1; unsigned int execonly:1; unsigned int cr0_pg:1; + unsigned int cr4_pae:1; unsigned int cr4_pse:1; unsigned int cr4_pke:1; unsigned int cr4_smap:1; diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index e10962dfc203..d9c7b45d231f 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -4781,6 +4781,7 @@ static union kvm_mmu_extended_role kvm_calc_mmu_role_ext(struct kvm_vcpu *vcpu) union kvm_mmu_extended_role ext = {0}; ext.cr0_pg = !!is_paging(vcpu); + ext.cr4_pae = !!is_pae(vcpu); ext.cr4_smep = !!kvm_read_cr4_bits(vcpu, X86_CR4_SMEP); ext.cr4_smap = !!kvm_read_cr4_bits(vcpu, X86_CR4_SMAP); ext.cr4_pse = !!is_pse(vcpu);