From 2e408936b6de5a7540880ae40bc7ce43102053ba Mon Sep 17 00:00:00 2001
From: KarimAllah Ahmed <karahmed@amazon.de>
Date: Thu, 31 Jan 2019 21:24:31 +0100
Subject: [PATCH] X86/nVMX: handle_vmon: Read 4 bytes from guest memory
Read the data directly from guest memory instead of the map->read->unmap
sequence. This also avoids using kvm_vcpu_gpa_to_page() and kmap() which
assumes that there is a "struct page" for guest memory.
Suggested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/vmx/nested.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index b46136b099b8e..9b1973cc1e75d 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4264,7 +4264,7 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
{
int ret;
gpa_t vmptr;
- struct page *page;
+ uint32_t revision;
struct vcpu_vmx *vmx = to_vmx(vcpu);
const u64 VMXON_NEEDED_FEATURES = FEATURE_CONTROL_LOCKED
| FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;
@@ -4313,18 +4313,10 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
if (!PAGE_ALIGNED(vmptr) || (vmptr >> cpuid_maxphyaddr(vcpu)))
return nested_vmx_failInvalid(vcpu);
- page = kvm_vcpu_gpa_to_page(vcpu, vmptr);
- if (is_error_page(page))
+ if (kvm_read_guest(vcpu->kvm, vmptr, &revision, sizeof(revision)) ||
+ revision != VMCS12_REVISION)
return nested_vmx_failInvalid(vcpu);
- if (*(u32 *)kmap(page) != VMCS12_REVISION) {
- kunmap(page);
- kvm_release_page_clean(page);
- return nested_vmx_failInvalid(vcpu);
- }
- kunmap(page);
- kvm_release_page_clean(page);
-
vmx->nested.vmxon_ptr = vmptr;
ret = enter_vmx_operation(vcpu);
if (ret)
--
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