From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Roman Kagan" <rkagan@virtuozzo.com>,
"K. Y. Srinivasan" <kys@microsoft.com>,
"Haiyang Zhang" <haiyangz@microsoft.com>,
"Stephen Hemminger" <sthemmin@microsoft.com>,
"Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com>,
linux-kernel@vger.kernel.org, "Jim Mattson" <jmattson@google.com>,
"Liran Alon" <liran.alon@oracle.com>
Subject: [PATCH v6 08/13] x86/kvm/lapic: preserve gfn_to_hva_cache len on cache reinit
Date: Tue, 16 Oct 2018 18:50:06 +0200 [thread overview]
Message-ID: <20181016165011.6607-9-vkuznets@redhat.com> (raw)
In-Reply-To: <20181016165011.6607-1-vkuznets@redhat.com>
vcpu->arch.pv_eoi is accessible through both HV_X64_MSR_VP_ASSIST_PAGE and
MSR_KVM_PV_EOI_EN so on migration userspace may try to restore them in any
order. Values match, however, kvm_lapic_enable_pv_eoi() uses different
length: for Hyper-V case it's the whole struct hv_vp_assist_page, for KVM
native case it is 8. In case we restore KVM-native MSR last cache will
be reinitialized with len=8 so trying to access VP assist page beyond
8 bytes with kvm_read_guest_cached() will fail.
Check if we re-initializing cache for the same address and preserve length
in case it was greater.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/lapic.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 79358fd6a71c..3cd227ff807f 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2647,14 +2647,22 @@ int kvm_hv_vapic_msr_read(struct kvm_vcpu *vcpu, u32 reg, u64 *data)
int kvm_lapic_enable_pv_eoi(struct kvm_vcpu *vcpu, u64 data, unsigned long len)
{
u64 addr = data & ~KVM_MSR_ENABLED;
+ struct gfn_to_hva_cache *ghc = &vcpu->arch.pv_eoi.data;
+ unsigned long new_len;
+
if (!IS_ALIGNED(addr, 4))
return 1;
vcpu->arch.pv_eoi.msr_val = data;
if (!pv_eoi_enabled(vcpu))
return 0;
- return kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.pv_eoi.data,
- addr, len);
+
+ if (addr == ghc->gpa && len <= ghc->len)
+ new_len = ghc->len;
+ else
+ new_len = len;
+
+ return kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc, addr, new_len);
}
void kvm_apic_accept_events(struct kvm_vcpu *vcpu)
--
2.17.1
next prev parent reply other threads:[~2018-10-16 16:50 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-16 16:49 [PATCH v6 00/13] KVM: nVMX: Enlightened VMCS for Hyper-V on KVM Vitaly Kuznetsov
2018-10-16 16:49 ` [PATCH v6 01/13] KVM: hyperv: define VP assist page helpers Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 02/13] KVM: VMX: refactor evmcs_sanitize_exec_ctrls() Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 03/13] KVM: nVMX: add KVM_CAP_HYPERV_ENLIGHTENED_VMCS capability Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 04/13] KVM: nVMX: add enlightened VMCS state Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 05/13] KVM: nVMX: implement enlightened VMPTRLD and VMCLEAR Vitaly Kuznetsov
2018-12-12 23:19 ` Jim Mattson
2018-12-13 10:26 ` Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 06/13] KVM: nVMX: optimize prepare_vmcs02{,_full} for Enlightened VMCS case Vitaly Kuznetsov
2018-10-16 21:55 ` Paolo Bonzini
2018-10-17 14:47 ` Vitaly Kuznetsov
2018-10-17 17:02 ` Paolo Bonzini
2018-10-17 17:08 ` Jim Mattson
2018-10-17 17:17 ` Paolo Bonzini
2018-10-18 11:14 ` Vitaly Kuznetsov
2018-10-18 12:42 ` Paolo Bonzini
2018-10-16 16:50 ` [PATCH v6 07/13] x86/kvm/hyperv: don't clear VP assist pages on init Vitaly Kuznetsov
2018-10-16 16:50 ` Vitaly Kuznetsov [this message]
2018-10-16 16:50 ` [PATCH v6 09/13] x86/kvm/nVMX: allow bare VMXON state migration Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 10/13] KVM: selftests: state_test: test bare VMXON migration Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 11/13] x86/kvm/nVMX: nested state migration for Enlightened VMCS Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 12/13] tools/headers: update kvm.h Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 13/13] KVM: selftests: add Enlightened VMCS test Vitaly Kuznetsov
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