From: Maxim Levitsky <mlevitsk@redhat.com>
To: kvm@vger.kernel.org
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>, Joerg Roedel <joro@8bytes.org>,
Ingo Molnar <mingo@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
Wanpeng Li <wanpengli@tencent.com>,
Borislav Petkov <bp@alien8.de>, Jim Mattson <jmattson@google.com>,
linux-kernel@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Maxim Levitsky <mlevitsk@redhat.com>
Subject: [PATCH v5 2/4] KVM: x86: report negative values from wrmsr to userspace
Date: Mon, 21 Sep 2020 16:19:21 +0300 [thread overview]
Message-ID: <20200921131923.120833-3-mlevitsk@redhat.com> (raw)
In-Reply-To: <20200921131923.120833-1-mlevitsk@redhat.com>
This will allow us to make some MSR writes fatal to the guest
(e.g when out of memory condition occurs)
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/emulate.c | 7 +++++--
arch/x86/kvm/x86.c | 5 +++--
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 1d450d7710d63..d855304f5a509 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3702,13 +3702,16 @@ static int em_dr_write(struct x86_emulate_ctxt *ctxt)
static int em_wrmsr(struct x86_emulate_ctxt *ctxt)
{
u64 msr_data;
+ int ret;
msr_data = (u32)reg_read(ctxt, VCPU_REGS_RAX)
| ((u64)reg_read(ctxt, VCPU_REGS_RDX) << 32);
- if (ctxt->ops->set_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), msr_data))
+
+ ret = ctxt->ops->set_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), msr_data);
+ if (ret > 0)
return emulate_gp(ctxt, 0);
- return X86EMUL_CONTINUE;
+ return ret < 0 ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE;
}
static int em_rdmsr(struct x86_emulate_ctxt *ctxt)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 063d70e736f7f..b6c67ab7c4f34 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1612,15 +1612,16 @@ int kvm_emulate_wrmsr(struct kvm_vcpu *vcpu)
{
u32 ecx = kvm_rcx_read(vcpu);
u64 data = kvm_read_edx_eax(vcpu);
+ int ret = kvm_set_msr(vcpu, ecx, data);
- if (kvm_set_msr(vcpu, ecx, data)) {
+ if (ret > 0) {
trace_kvm_msr_write_ex(ecx, data);
kvm_inject_gp(vcpu, 0);
return 1;
}
trace_kvm_msr_write(ecx, data);
- return kvm_skip_emulated_instruction(vcpu);
+ return ret < 0 ? ret : kvm_skip_emulated_instruction(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_emulate_wrmsr);
--
2.26.2
next prev parent reply other threads:[~2020-09-21 13:19 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-21 13:19 [PATCH v5 0/4] KVM: nSVM: ondemand nested state allocation Maxim Levitsky
2020-09-21 13:19 ` [PATCH v5 1/4] KVM: x86: xen_hvm_config: cleanup return values Maxim Levitsky
2020-09-21 13:19 ` Maxim Levitsky [this message]
2020-09-21 16:08 ` [PATCH v5 2/4] KVM: x86: report negative values from wrmsr to userspace Sean Christopherson
2020-09-22 16:13 ` Maxim Levitsky
2020-09-21 13:19 ` [PATCH v5 3/4] KVM: x86: allow kvm_x86_ops.set_efer to return a value Maxim Levitsky
[not found] ` <20200921154151.GA23807@linux.intel.com>
2020-09-22 16:05 ` Maxim Levitsky
2020-09-21 13:19 ` [PATCH v5 4/4] KVM: nSVM: implement ondemand allocation of the nested state Maxim Levitsky
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