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From: KarimAllah Ahmed <karahmed@amazon.de>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	pbonzini@redhat.com, rkrcmar@redhat.com
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Subject: [PATCH v2 01/12] X86/nVMX: handle_vmon: Read 4 bytes from guest memory
Date: Sun, 15 Apr 2018 23:53:07 +0200	[thread overview]
Message-ID: <1523829198-13236-2-git-send-email-karahmed@amazon.de> (raw)
In-Reply-To: <1523829198-13236-1-git-send-email-karahmed@amazon.de>

Read the data directly from guest memory instead 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>
---
v1 -> v2:
- Massage commit message a bit.
---
 arch/x86/kvm/vmx.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 55ab0ca..77fc1ee 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7672,7 +7672,7 @@ 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;
@@ -7718,19 +7718,11 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
 		return kvm_skip_emulated_instruction(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) {
 		nested_vmx_failInvalid(vcpu);
 		return kvm_skip_emulated_instruction(vcpu);
 	}
-	if (*(u32 *)kmap(page) != VMCS12_REVISION) {
-		kunmap(page);
-		kvm_release_page_clean(page);
-		nested_vmx_failInvalid(vcpu);
-		return kvm_skip_emulated_instruction(vcpu);
-	}
-	kunmap(page);
-	kvm_release_page_clean(page);
 
 	vmx->nested.vmxon_ptr = vmptr;
 	ret = enter_vmx_operation(vcpu);
-- 
2.7.4

  reply	other threads:[~2018-04-15 21:55 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-15 21:53 [PATCH v2 00/12] KVM/X86: Introduce a new guest mapping interface KarimAllah Ahmed
2018-04-15 21:53 ` KarimAllah Ahmed [this message]
2018-04-15 21:53 ` [PATCH v2 02/12] X86/nVMX: handle_vmptrld: Copy the VMCS12 directly from guest memory KarimAllah Ahmed
2018-04-15 21:53 ` [PATCH v2 03/12] X86/nVMX: Update the PML table without mapping and unmapping the page KarimAllah Ahmed
2018-04-16 11:10   ` Paolo Bonzini
2018-04-15 21:53 ` [PATCH v2 04/12] X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs KarimAllah Ahmed
2018-04-15 21:53 ` [PATCH v2 05/12] KVM: Introduce a new guest mapping API KarimAllah Ahmed
2018-04-15 21:53 ` [PATCH v2 06/12] KVM/nVMX: Use kvm_vcpu_map when mapping the L1 MSR bitmap KarimAllah Ahmed
2018-04-15 21:53 ` [PATCH v2 07/12] KVM/nVMX: Use kvm_vcpu_map when mapping the virtual APIC page KarimAllah Ahmed
2018-04-15 21:53 ` [PATCH v2 08/12] KVM/nVMX: Use kvm_vcpu_map when mapping the posted interrupt descriptor table KarimAllah Ahmed
2018-04-15 21:53 ` [PATCH v2 09/12] KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated KarimAllah Ahmed
2018-04-15 21:53 ` [PATCH v2 10/12] KVM/X86: hyperv: Use kvm_vcpu_map in synic_clear_sint_msg_pending KarimAllah Ahmed
2018-04-15 21:53 ` [PATCH v2 11/12] KVM/X86: hyperv: Use kvm_vcpu_map in synic_deliver_msg KarimAllah Ahmed
2018-04-15 21:53 ` [PATCH v2 12/12] KVM/nSVM: Use the new mapping API for mapping guest memory KarimAllah Ahmed
2018-04-16 11:10 ` [PATCH v2 00/12] KVM/X86: Introduce a new guest mapping interface Paolo Bonzini
2018-04-16 12:09   ` Raslan, KarimAllah
2018-04-16 12:27     ` Paolo Bonzini
2018-05-15 16:06       ` Konrad Rzeszutek Wilk
2018-05-22 15:43         ` Raslan, KarimAllah
2018-07-10 12:06   ` Raslan, KarimAllah
2018-07-11 10:26     ` Paolo Bonzini

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