On Wed, Jan 09, 2019 at 10:42:02AM +0100, KarimAllah Ahmed wrote:
> 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.
>
> As a side-effect of using kvm_write_guest_page the page is also properly
> marked as dirty.
>
> Signed-off-by: KarimAllah Ahmed <karahmed@xxxxxxxxx>
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> ---
> 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/vmx.c | 14 +++++---------
> 1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 4d39f73..71d88df 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7199,9 +7199,7 @@ 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);
> @@ -7221,15 +7219,13 @@ 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
>
