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| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-07-14 04:57:32 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-08-09 19:51:50 +0300 |
| commit | 05487215e6b9732cc4ad0e83e465b33182200ad5 (patch) | |
| tree | c0ad298056442f7b6a6bf4a192db1dca9d61b42d /arch/x86 | |
| parent | 06a81c1c7db9bd5de0bd38cd5acc44bb22b99150 (diff) | |
| download | linux-05487215e6b9732cc4ad0e83e465b33182200ad5.tar.xz | |
KVM: x86: Don't attempt to load PDPTRs when 64-bit mode is enabled
Don't attempt to load PDPTRs if EFER.LME=1, i.e. if 64-bit mode is
enabled. A recent change to reload the PDTPRs when CR0.CD or CR0.NW is
toggled botched the EFER.LME handling and sends KVM down the PDTPR path
when is_paging() is true, i.e. when the guest toggles CD/NW in 64-bit
mode.
Split the CR0 checks for 64-bit vs. 32-bit PAE into separate paths. The
64-bit path is specifically checking state when paging is toggled on,
i.e. CR0.PG transititions from 0->1. The PDPTR path now needs to run if
the new CR0 state has paging enabled, irrespective of whether paging was
already enabled. Trying to shave a few cycles to make the PDPTR path an
"else if" case is a mess.
Fixes: d42e3fae6faed ("kvm: x86: Read PDPTEs on CR0.CD and CR0.NW changes")
Cc: Jim Mattson <jmattson@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Peter Shier <pshier@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200714015732.32426-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/x86.c | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 12ea77f99ff3..2db369a64f29 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -820,22 +820,22 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) if ((cr0 & X86_CR0_PG) && !(cr0 & X86_CR0_PE)) return 1; - if (cr0 & X86_CR0_PG) { #ifdef CONFIG_X86_64 - if (!is_paging(vcpu) && (vcpu->arch.efer & EFER_LME)) { - int cs_db, cs_l; + if ((vcpu->arch.efer & EFER_LME) && !is_paging(vcpu) && + (cr0 & X86_CR0_PG)) { + int cs_db, cs_l; - if (!is_pae(vcpu)) - return 1; - kvm_x86_ops.get_cs_db_l_bits(vcpu, &cs_db, &cs_l); - if (cs_l) - return 1; - } else -#endif - if (is_pae(vcpu) && ((cr0 ^ old_cr0) & pdptr_bits) && - !load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu))) + if (!is_pae(vcpu)) + return 1; + kvm_x86_ops.get_cs_db_l_bits(vcpu, &cs_db, &cs_l); + if (cs_l) return 1; } +#endif + if (!(vcpu->arch.efer & EFER_LME) && (cr0 & X86_CR0_PG) && + is_pae(vcpu) && ((cr0 ^ old_cr0) & pdptr_bits) && + !load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu))) + return 1; if (!(cr0 & X86_CR0_PG) && kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE)) return 1; |