[PATCH v2 03/12] X86/nVMX: Update the PML table without mapping and unmapping the page

KarimAllah Ahmed
2018-04-15T21:55:00Z

Update the PML table without mapping and unmapping the page. This also
avoids using kvm_vcpu_gpa_to_page(..) which assumes that there is a "struct
page" for guest memory.

Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
---
v1 -> v2:
- Use kvm_write_guest_page instead of kvm_write_guest (pbonzini)
- Do not use pointer arithmetic for pml_address (pbonzini)
---
arch/x86/kvm/vmx.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 810ba7a..179061d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -12294,9 +12294,7 @@ 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;
- u64 *pml_address;
+ gpa_t gpa, dst;

if (is_guest_mode(vcpu)) {
WARN_ON_ONCE(vmx->nested.pml_full);
@@ -12316,15 +12314,13 @@ static int vmx_write_pml_buffer(struct kvm_vcpu *vcpu)
}

gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS) & ~0xFFFull;
+ dst = vmcs12->pml_address + sizeof(u64) * vmcs12->guest_pml_index;

- page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->pml_address);
- if (is_error_page(page))
+ if (kvm_write_guest_page(vcpu->kvm, gpa_to_gfn(dst), &gpa,
+ offset_in_page(dst), sizeof(gpa)))
return 0;

- pml_address = kmap(page);
- pml_address[vmcs12->guest_pml_index--] = gpa;
- kunmap(page);
- kvm_release_page_clean(page);
+ vmcs12->guest_pml_index--;
}

return 0;
--
2.7.4