提交 6d6f7a5a 编写于 作者: S Sean Christopherson 提交者: Zheng Zengkai

KVM: x86: Signal #GP, not -EPERM, on bad WRMSR(MCi_CTL/STATUS)

stable inclusion
from stable-v5.10.137
commit e7ccee2f09b06303fb39f8cb19a2c21d388dc4e6
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e7ccee2f09b06303fb39f8cb19a2c21d388dc4e6

--------------------------------

[ Upstream commit 2368048b ]

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: 890ca9ae ("KVM: Add MCE support")
Fixes: 9ffd986c ("KVM: X86: #GP when guest attempts to write MCi_STATUS register w/o 0")
Cc: stable@vger.kernel.org
Signed-off-by: NSean Christopherson <seanjc@google.com>
Reviewed-by: NJim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20220512222716.4112548-2-seanjc@google.comSigned-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
上级 e04324bf
......@@ -2919,13 +2919,13 @@ 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;
......
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