diff options
author | Sean Christopherson <seanjc@google.com> | 2022-05-13 01:27:14 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-21 16:16:17 +0300 |
commit | e7ccee2f09b06303fb39f8cb19a2c21d388dc4e6 (patch) | |
tree | 45276ecfcaf12989ef9a4d396b55de2b8bfb95d2 /arch | |
parent | f5385a590df78d7649876a2087646090e867e6eb (diff) | |
download | linux-e7ccee2f09b06303fb39f8cb19a2c21d388dc4e6.tar.xz |
KVM: x86: Signal #GP, not -EPERM, on bad WRMSR(MCi_CTL/STATUS)
[ Upstream commit 2368048bf5c2ec4b604ac3431564071e89a0bc71 ]
Return '1', not '-1', when handling an illegal WRMSR to a MCi_CTL or
MCi_STATUS MSR. The behavior of "all zeros' or "all ones" for CTL MSRs
is architectural, as is the "only zeros" behavior for STATUS MSRs. I.e.
the intent is to inject a #GP, not exit to userspace due to an unhandled
emulation case. Returning '-1' gets interpreted as -EPERM up the stack
and effecitvely kills the guest.
Fixes: 890ca9aefa78 ("KVM: Add MCE support")
Fixes: 9ffd986c6e4e ("KVM: X86: #GP when guest attempts to write MCi_STATUS register w/o 0")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20220512222716.4112548-2-seanjc@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kvm/x86.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 23a5e5880615..98422a53bb1e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2869,13 +2869,13 @@ static int set_msr_mce(struct kvm_vcpu *vcpu, struct msr_data *msr_info) */ if ((offset & 0x3) == 0 && data != 0 && (data | (1 << 10) | 1) != ~(u64)0) - return -1; + return 1; /* MCi_STATUS */ if (!msr_info->host_initiated && (offset & 0x3) == 1 && data != 0) { if (!can_set_mci_status(vcpu)) - return -1; + return 1; } vcpu->arch.mce_banks[offset] = data; |