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From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
	vkuznets@redhat.com
Subject: [PATCH 12/43] KVM: nVMX: Add helpers to identify shadowed VMCS fields
Date: Thu, 13 Jun 2019 19:02:58 +0200
Message-ID: <1560445409-17363-13-git-send-email-pbonzini@redhat.com> (raw)
In-Reply-To: <1560445409-17363-1-git-send-email-pbonzini@redhat.com>

From: Sean Christopherson <sean.j.christopherson@intel.com>

So that future optimizations related to shadowed fields don't need to
define their own switch statement.

Add a BUILD_BUG_ON() to ensure at least one of the types (RW vs RO) is
defined when including vmcs_shadow_fields.h (guess who keeps mistyping
SHADOW_FIELD_RO as SHADOW_FIELD_R0).

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/nested.c             | 71 ++++++++++++++++++++---------------
 arch/x86/kvm/vmx/vmcs_shadow_fields.h |  4 ++
 2 files changed, 44 insertions(+), 31 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index fc2b8f4cf45f..a6fe6cfe96f6 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4420,6 +4420,29 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
 	return nested_vmx_succeed(vcpu);
 }
 
+static bool is_shadow_field_rw(unsigned long field)
+{
+	switch (field) {
+#define SHADOW_FIELD_RW(x, y) case x:
+#include "vmcs_shadow_fields.h"
+		return true;
+	default:
+		break;
+	}
+	return false;
+}
+
+static bool is_shadow_field_ro(unsigned long field)
+{
+	switch (field) {
+#define SHADOW_FIELD_RO(x, y) case x:
+#include "vmcs_shadow_fields.h"
+		return true;
+	default:
+		break;
+	}
+	return false;
+}
 
 static int handle_vmwrite(struct kvm_vcpu *vcpu)
 {
@@ -4503,41 +4526,27 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
 	vmcs12_write_any(vmcs12, field, offset, field_value);
 
 	/*
-	 * Do not track vmcs12 dirty-state if in guest-mode
-	 * as we actually dirty shadow vmcs12 instead of vmcs12.
+	 * Do not track vmcs12 dirty-state if in guest-mode as we actually
+	 * dirty shadow vmcs12 instead of vmcs12.  Fields that can be updated
+	 * by L1 without a vmexit are always updated in the vmcs02, i.e' don't
+	 * "dirty" vmcs12, all others go down the prepare_vmcs02() slow path.
 	 */
-	if (!is_guest_mode(vcpu)) {
-		switch (field) {
-#define SHADOW_FIELD_RW(x, y) case x:
-#include "vmcs_shadow_fields.h"
-			/*
-			 * The fields that can be updated by L1 without a vmexit are
-			 * always updated in the vmcs02, the others go down the slow
-			 * path of prepare_vmcs02.
-			 */
-			break;
-
-#define SHADOW_FIELD_RO(x, y) case x:
-#include "vmcs_shadow_fields.h"
-			/*
-			 * L1 can read these fields without exiting, ensure the
-			 * shadow VMCS is up-to-date.
-			 */
-			if (enable_shadow_vmcs) {
-				preempt_disable();
-				vmcs_load(vmx->vmcs01.shadow_vmcs);
+	if (!is_guest_mode(vcpu) && !is_shadow_field_rw(field)) {
+		/*
+		 * L1 can read these fields without exiting, ensure the
+		 * shadow VMCS is up-to-date.
+		 */
+		if (enable_shadow_vmcs && is_shadow_field_ro(field)) {
+			preempt_disable();
+			vmcs_load(vmx->vmcs01.shadow_vmcs);
 
-				__vmcs_writel(field, field_value);
+			__vmcs_writel(field, field_value);
 
-				vmcs_clear(vmx->vmcs01.shadow_vmcs);
-				vmcs_load(vmx->loaded_vmcs->vmcs);
-				preempt_enable();
-			}
-			/* fall through */
-		default:
-			vmx->nested.dirty_vmcs12 = true;
-			break;
+			vmcs_clear(vmx->vmcs01.shadow_vmcs);
+			vmcs_load(vmx->loaded_vmcs->vmcs);
+			preempt_enable();
 		}
+		vmx->nested.dirty_vmcs12 = true;
 	}
 
 	return nested_vmx_succeed(vcpu);
diff --git a/arch/x86/kvm/vmx/vmcs_shadow_fields.h b/arch/x86/kvm/vmx/vmcs_shadow_fields.h
index 2cfa19ca158e..4cea018ba285 100644
--- a/arch/x86/kvm/vmx/vmcs_shadow_fields.h
+++ b/arch/x86/kvm/vmx/vmcs_shadow_fields.h
@@ -1,3 +1,7 @@
+#if !defined(SHADOW_FIELD_RO) && !defined(SHADOW_FIELD_RW)
+BUILD_BUG_ON(1)
+#endif
+
 #ifndef SHADOW_FIELD_RO
 #define SHADOW_FIELD_RO(x, y)
 #endif
-- 
1.8.3.1



  parent reply index

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-13 17:02 [PATCH 00/43] VMX optimizations Paolo Bonzini
2019-06-13 17:02 ` [PATCH 01/43] KVM: VMX: Fix handling of #MC that occurs during VM-Entry Paolo Bonzini
2019-06-13 17:24   ` Jim Mattson
2019-06-13 17:02 ` [PATCH 02/43] kvm: nVMX: small cleanup in handle_exception Paolo Bonzini
2019-06-13 17:02 ` [PATCH 03/43] KVM: VMX: Read cached VM-Exit reason to detect external interrupt Paolo Bonzini
2019-06-13 17:02 ` [PATCH 04/43] KVM: VMX: Store the host kernel's IDT base in a global variable Paolo Bonzini
2019-06-13 17:02 ` [PATCH 05/43] KVM: x86: Move kvm_{before,after}_interrupt() calls to vendor code Paolo Bonzini
2019-06-13 17:02 ` [PATCH 06/43] KVM: VMX: Handle NMIs, #MCs and async #PFs in common irqs-disabled fn Paolo Bonzini
2019-06-13 17:02 ` [PATCH 07/43] KVM: nVMX: Intercept VMWRITEs to read-only shadow VMCS fields Paolo Bonzini
2019-06-13 17:02 ` [PATCH 08/43] KVM: nVMX: Intercept VMWRITEs to GUEST_{CS,SS}_AR_BYTES Paolo Bonzini
2019-06-13 17:02 ` [PATCH 09/43] KVM: nVMX: Track vmcs12 offsets for shadowed VMCS fields Paolo Bonzini
2019-06-13 17:02 ` [PATCH 10/43] KVM: nVMX: Lift sync_vmcs12() out of prepare_vmcs12() Paolo Bonzini
2019-06-13 17:02 ` [PATCH 11/43] KVM: nVMX: Use descriptive names for VMCS sync functions and flags Paolo Bonzini
2019-06-13 17:02 ` Paolo Bonzini [this message]
2019-06-14 16:10   ` [PATCH 12/43] KVM: nVMX: Add helpers to identify shadowed VMCS fields Sean Christopherson
2019-06-13 17:02 ` [PATCH 13/43] KVM: nVMX: Sync rarely accessed guest fields only when needed Paolo Bonzini
2019-06-13 17:03 ` [PATCH 14/43] KVM: nVMX: Rename prepare_vmcs02_*_full to prepare_vmcs02_*_rare Paolo Bonzini
2019-06-13 17:03 ` [PATCH 15/43] KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR_PAT with bad value Paolo Bonzini
2019-06-13 17:03 ` [PATCH 16/43] KVM: nVMX: Always sync GUEST_BNDCFGS when it comes from vmcs01 Paolo Bonzini
     [not found]   ` <20190615221602.93C5721851@mail.kernel.org>
2019-06-15 22:40     ` Liran Alon
2019-06-13 17:03 ` [PATCH 17/43] KVM: nVMX: Write ENCLS-exiting bitmap once per vmcs02 Paolo Bonzini
2019-06-13 17:03 ` [PATCH 18/43] KVM: nVMX: Don't rewrite GUEST_PML_INDEX during nested VM-Entry Paolo Bonzini
2019-06-13 17:03 ` [PATCH 19/43] KVM: VMX: simplify vmx_prepare_switch_to_{guest,host} Paolo Bonzini
2019-06-13 17:03 ` [PATCH 20/43] KVM: nVMX: Don't "put" vCPU or host state when switching VMCS Paolo Bonzini
2019-06-13 17:03 ` [PATCH 21/43] KVM: nVMX: Don't reread VMCS-agnostic " Paolo Bonzini
2019-06-14 16:25   ` Sean Christopherson
2019-06-13 17:03 ` [PATCH 22/43] KVM: nVMX: Don't dump VMCS if virtual APIC page can't be mapped Paolo Bonzini
2019-06-17 19:17   ` Radim Krčmář
2019-06-17 20:07     ` Sean Christopherson
2019-06-18  9:43       ` Paolo Bonzini
2019-06-13 17:03 ` [PATCH 23/43] KVM: nVMX: Don't speculatively write virtual-APIC page address Paolo Bonzini
2019-06-13 17:03 ` [PATCH 24/43] KVM: nVMX: Don't speculatively write APIC-access " Paolo Bonzini
2019-06-13 17:03 ` [PATCH 25/43] KVM: nVMX: Update vmcs12 for MSR_IA32_CR_PAT when it's written Paolo Bonzini
2019-06-13 17:03 ` [PATCH 26/43] KVM: nVMX: Update vmcs12 for SYSENTER MSRs when they're written Paolo Bonzini
2019-06-13 17:03 ` [PATCH 27/43] KVM: nVMX: Update vmcs12 for MSR_IA32_DEBUGCTLMSR when it's written Paolo Bonzini
2019-06-13 17:03 ` [PATCH 28/43] KVM: nVMX: Don't update GUEST_BNDCFGS if it's clean in HV eVMCS Paolo Bonzini
2019-06-13 17:03 ` [PATCH 29/43] KVM: x86: introduce is_pae_paging Paolo Bonzini
2019-06-13 17:03 ` [PATCH 30/43] KVM: nVMX: Copy PDPTRs to/from vmcs12 only when necessary Paolo Bonzini
2019-06-13 17:03 ` [PATCH 31/43] KVM: nVMX: Use adjusted pin controls for vmcs02 Paolo Bonzini
2019-06-13 17:03 ` [PATCH 32/43] KVM: VMX: Add builder macros for shadowing controls Paolo Bonzini
2019-06-13 17:03 ` [PATCH 33/43] KVM: VMX: Shadow VMCS pin controls Paolo Bonzini
2019-06-13 17:03 ` [PATCH 34/43] KVM: VMX: Shadow VMCS primary execution controls Paolo Bonzini
2019-06-13 17:03 ` [PATCH 35/43] KVM: VMX: Shadow VMCS secondary " Paolo Bonzini
2019-06-13 17:03 ` [PATCH 36/43] KVM: nVMX: Shadow VMCS controls on a per-VMCS basis Paolo Bonzini
2019-06-13 17:03 ` [PATCH 37/43] KVM: nVMX: Don't reset VMCS controls shadow on VMCS switch Paolo Bonzini
2019-06-13 17:03 ` [PATCH 38/43] KVM: VMX: Explicitly initialize controls shadow at VMCS allocation Paolo Bonzini
2019-06-13 17:03 ` [PATCH 39/43] KVM: nVMX: Preserve last USE_MSR_BITMAPS when preparing vmcs02 Paolo Bonzini
2019-06-13 17:03 ` [PATCH 40/43] KVM: nVMX: Preset *DT exiting in vmcs02 when emulating UMIP Paolo Bonzini
2019-06-13 17:03 ` [PATCH 41/43] KVM: VMX: Drop hv_timer_armed from 'struct loaded_vmcs' Paolo Bonzini
2019-06-13 17:03 ` [PATCH 42/43] KVM: VMX: Leave preemption timer running when it's disabled Paolo Bonzini
2019-06-14 16:34   ` Sean Christopherson
2019-06-13 17:03 ` [PATCH 43/43] KVM: nVMX: shadow pin based execution controls Paolo Bonzini
2019-06-14 16:34   ` Sean Christopherson

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