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Subject[RFC 08/12] KVM/VMX: Use the new host mapping API for mapping nested PML
Date
For nested guests the PML page was mapped to the host kernel using
kvm_vcpu_gpa_to_page which assumes that all guest memory is backed by a
"struct page". This breaks guests that have their memory outside the kernel
control.

Switch to the new host mapping API which takes care of this use-case as
well.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
---
arch/x86/kvm/vmx.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 7177176..620b4ff 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11866,7 +11866,7 @@ static int vmx_write_pml_buffer(struct kvm_vcpu *vcpu)
struct vmcs12 *vmcs12;
struct vcpu_vmx *vmx = to_vmx(vcpu);
gpa_t gpa;
- struct page *page = NULL;
+ struct kvm_host_mapping mapping;
u64 *pml_address;

if (is_guest_mode(vcpu)) {
@@ -11888,14 +11888,13 @@ static int vmx_write_pml_buffer(struct kvm_vcpu *vcpu)

gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS) & ~0xFFFull;

- page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->pml_address);
- if (is_error_page(page))
+ if (!kvm_vcpu_gpa_to_host_mapping(vcpu, vmcs12->pml_address, &mapping, true))
return 0;

- pml_address = kmap(page);
+ pml_address = mapping.kaddr;
pml_address[vmcs12->guest_pml_index--] = gpa;
- kunmap(page);
- kvm_release_page_clean(page);
+
+ kvm_release_host_mapping(&mapping, false);
}

return 0;
--
2.7.4
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