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| author |   Krish Sadhukhan <krish.sadhukhan@oracle.com> | 2020-01-15 19:54:32 -0500 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2020-01-27 19:59:55 +0100 |
| commit | b91991bf6b707482953c094dbd9615f6382ba2cb (patch) | |
| tree | a27309345c916f18b7452f5224bc0715ceaf05c7 | |
| parent | KVM: remove unused guest_enter (diff) | |
| download | linux-dev-b91991bf6b707482953c094dbd9615f6382ba2cb.tar.xz linux-dev-b91991bf6b707482953c094dbd9615f6382ba2cb.zip | |
KVM: nVMX: Check GUEST_DR7 on vmentry of nested guests
According to section "Checks on Guest Control Registers, Debug Registers, and
and MSRs" in Intel SDM vol 3C, the following checks are performed on vmentry
of nested guests:
If the "load debug controls" VM-entry control is 1, bits 63:32 in the DR7
field must be 0.
In KVM, GUEST_DR7 is set prior to the vmcs02 VM-entry by kvm_set_dr() and the
latter synthesizes a #GP if any bit in the high dword in the former is set.
Hence this field needs to be checked in software.
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.h | 6 |
3 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 53ea65070b5a..95b3f4306ac2 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2887,6 +2887,10 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu, CC(!nested_guest_cr4_valid(vcpu, vmcs12->guest_cr4))) return -EINVAL; + if ((vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS) && + CC(!kvm_dr7_valid(vmcs12->guest_dr7))) + return -EINVAL; + if ((vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PAT) && CC(!kvm_pat_valid(vmcs12->guest_ia32_pat))) return -EINVAL; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 48cd4e191b9c..baf89d4bc653 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1082,7 +1082,7 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) case 5: /* fall through */ default: /* 7 */ - if (val & 0xffffffff00000000ULL) + if (!kvm_dr7_valid(val)) return -1; /* #GP */ vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1; kvm_update_dr7(vcpu); diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index e007b61b932a..2d2ff855773b 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -357,6 +357,12 @@ static inline bool kvm_pat_valid(u64 data) return (data | ((data & 0x0202020202020202ull) << 1)) == data; } +static inline bool kvm_dr7_valid(unsigned long data) +{ + /* Bits [63:32] are reserved */ + return !(data >> 32); +} + void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu); void kvm_load_host_xsave_state(struct kvm_vcpu *vcpu); u64 kvm_spec_ctrl_valid_bits(struct kvm_vcpu *vcpu); |