linux-kernel - [PATCH 03/10] X86/nVMX: Update the PML table without mapping and unmapping the page

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Date:   Wed, 21 Feb 2018 18:47:14 +0100
From:   KarimAllah Ahmed <karahmed@...zon.de>
To:     x86@...nel.org, linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     hpa@...or.com, jmattson@...gle.com, mingo@...hat.com,
        pbonzini@...hat.com, rkrcmar@...hat.com, tglx@...utronix.de,
        KarimAllah Ahmed <karahmed@...zon.de>
Subject: [PATCH 03/10] X86/nVMX: Update the PML table without mapping and unmapping the page

... which 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@...zon.de>
---
 arch/x86/kvm/vmx.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e5653d2..0a98d1a 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -12111,9 +12111,7 @@ 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);
@@ -12133,15 +12131,12 @@ static int vmx_write_pml_buffer(struct kvm_vcpu *vcpu)
 		}
 
 		gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS) & ~0xFFFull;
+		dst = (gpa_t)(((u64 *)vmcs12->pml_address) + vmcs12->guest_pml_index);
 
-		page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->pml_address);
-		if (is_error_page(page))
+		if (kvm_write_guest(vcpu->kvm, dst, &gpa, 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