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From: Joerg Roedel <joerg.roedel@amd.com>
To: Avi Kivity <avi@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>
Cc: <kvm@vger.kernel.org>, Joerg Roedel <joerg.roedel@amd.com>
Subject: [PATCH 13/13] KVM: SVM: Remove nested sel_cr0_write handling code
Date: Fri, 25 Mar 2011 10:29:16 +0100	[thread overview]
Message-ID: <1301045356-25257-14-git-send-email-joerg.roedel@amd.com> (raw)
In-Reply-To: <1301045356-25257-1-git-send-email-joerg.roedel@amd.com>

This patch removes all the old code which handled the nested
selective cr0 write intercepts. This code was only in place
as a work-around until the instruction emulator is capable
of doing the same. This is the case with this patch-set and
so the code can be removed.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
 arch/x86/kvm/svm.c |   78 +++++++++++++++++----------------------------------
 1 files changed, 26 insertions(+), 52 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 1672e3c..37c0060 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -93,14 +93,6 @@ struct nested_state {
 	/* A VMEXIT is required but not yet emulated */
 	bool exit_required;
 
-	/*
-	 * If we vmexit during an instruction emulation we need this to restore
-	 * the l1 guest rip after the emulation
-	 */
-	unsigned long vmexit_rip;
-	unsigned long vmexit_rsp;
-	unsigned long vmexit_rax;
-
 	/* cache for intercepts of the guest */
 	u32 intercept_cr;
 	u32 intercept_dr;
@@ -1365,31 +1357,6 @@ static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
-	if (is_guest_mode(vcpu)) {
-		/*
-		 * We are here because we run in nested mode, the host kvm
-		 * intercepts cr0 writes but the l1 hypervisor does not.
-		 * But the L1 hypervisor may intercept selective cr0 writes.
-		 * This needs to be checked here.
-		 */
-		unsigned long old, new;
-
-		/* Remove bits that would trigger a real cr0 write intercept */
-		old = vcpu->arch.cr0 & SVM_CR0_SELECTIVE_MASK;
-		new = cr0 & SVM_CR0_SELECTIVE_MASK;
-
-		if (old == new) {
-			/* cr0 write with ts and mp unchanged */
-			svm->vmcb->control.exit_code = SVM_EXIT_CR0_SEL_WRITE;
-			if (nested_svm_exit_handled(svm) == NESTED_EXIT_DONE) {
-				svm->nested.vmexit_rip = kvm_rip_read(vcpu);
-				svm->nested.vmexit_rsp = kvm_register_read(vcpu, VCPU_REGS_RSP);
-				svm->nested.vmexit_rax = kvm_register_read(vcpu, VCPU_REGS_RAX);
-				return;
-			}
-		}
-	}
-
 #ifdef CONFIG_X86_64
 	if (vcpu->arch.efer & EFER_LME) {
 		if (!is_paging(vcpu) && (cr0 & X86_CR0_PG)) {
@@ -2676,6 +2643,29 @@ static int emulate_on_interception(struct vcpu_svm *svm)
 	return emulate_instruction(&svm->vcpu, 0) == EMULATE_DONE;
 }
 
+bool check_selective_cr0_intercepted(struct vcpu_svm *svm, unsigned long val)
+{
+	unsigned long cr0 = svm->vcpu.arch.cr0;
+	bool ret = false;
+	u64 intercept;
+
+	intercept = svm->nested.intercept;
+
+	if (!is_guest_mode(&svm->vcpu) ||
+	    (!(intercept & (1ULL << INTERCEPT_SELECTIVE_CR0))))
+		return false;
+
+	cr0 &= ~SVM_CR0_SELECTIVE_MASK;
+	val &= ~SVM_CR0_SELECTIVE_MASK;
+
+	if (cr0 ^ val) {
+		svm->vmcb->control.exit_code = SVM_EXIT_CR0_SEL_WRITE;
+		ret = (nested_svm_exit_handled(svm) == NESTED_EXIT_DONE);
+	}
+
+	return ret;
+}
+
 #define CR_VALID (1ULL << 63)
 
 static int cr_interception(struct vcpu_svm *svm)
@@ -2699,7 +2689,8 @@ static int cr_interception(struct vcpu_svm *svm)
 		val = kvm_register_read(&svm->vcpu, reg);
 		switch (cr) {
 		case 0:
-			err = kvm_set_cr0(&svm->vcpu, val);
+			if (!check_selective_cr0_intercepted(svm, val))
+				err = kvm_set_cr0(&svm->vcpu, val);
 			break;
 		case 3:
 			err = kvm_set_cr3(&svm->vcpu, val);
@@ -2744,23 +2735,6 @@ static int cr_interception(struct vcpu_svm *svm)
 	return 1;
 }
 
-static int cr0_write_interception(struct vcpu_svm *svm)
-{
-	struct kvm_vcpu *vcpu = &svm->vcpu;
-	int r;
-
-	r = cr_interception(svm);
-
-	if (svm->nested.vmexit_rip) {
-		kvm_register_write(vcpu, VCPU_REGS_RIP, svm->nested.vmexit_rip);
-		kvm_register_write(vcpu, VCPU_REGS_RSP, svm->nested.vmexit_rsp);
-		kvm_register_write(vcpu, VCPU_REGS_RAX, svm->nested.vmexit_rax);
-		svm->nested.vmexit_rip = 0;
-	}
-
-	return r;
-}
-
 static int dr_interception(struct vcpu_svm *svm)
 {
 	int reg, dr;
@@ -3048,7 +3022,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm) = {
 	[SVM_EXIT_READ_CR4]			= cr_interception,
 	[SVM_EXIT_READ_CR8]			= cr_interception,
 	[SVM_EXIT_CR0_SEL_WRITE]		= emulate_on_interception,
-	[SVM_EXIT_WRITE_CR0]			= cr0_write_interception,
+	[SVM_EXIT_WRITE_CR0]			= cr_interception,
 	[SVM_EXIT_WRITE_CR3]			= cr_interception,
 	[SVM_EXIT_WRITE_CR4]			= cr_interception,
 	[SVM_EXIT_WRITE_CR8]			= cr8_write_interception,
-- 
1.7.1



  parent reply	other threads:[~2011-03-25  9:29 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-25  9:29 [PATCH 0/13] KVM: Make the instruction emulator aware of Nested Virtualization v2 Joerg Roedel
2011-03-25  9:29 ` [PATCH 01/13] KVM: x86 emulator: add framework for instruction Joerg Roedel
2011-03-26  9:54   ` Avi Kivity
2011-03-27 12:56   ` Gleb Natapov
2011-03-28 10:19     ` Joerg Roedel
2011-03-25  9:29 ` [PATCH 02/13] KVM: x86 emulator: add SVM intercepts Joerg Roedel
2011-03-25  9:29 ` [PATCH 03/13] KVM: X86: Don't write-back cpu-state on X86EMUL_INTERCEPTED Joerg Roedel
2011-03-25  9:29 ` [PATCH 04/13] KVM: X86: Add x86 callback for intercept check Joerg Roedel
2011-03-26  9:23   ` Avi Kivity
2011-03-25  9:29 ` [PATCH 05/13] KVM: SVM: Add intercept check for emulated cr accesses Joerg Roedel
2011-03-26  9:37   ` Avi Kivity
2011-03-26 11:06     ` Joerg Roedel
2011-03-27  9:45       ` Avi Kivity
2011-03-25  9:29 ` [PATCH 06/13] KVM: SVM: Add intercept check for accessing dr registers Joerg Roedel
2011-03-25  9:29 ` [PATCH 07/13] KVM: SVM: Add intercept checks for descriptor table accesses Joerg Roedel
2011-03-26  9:43   ` Avi Kivity
2011-03-26 11:10     ` Joerg Roedel
2011-03-25  9:29 ` [PATCH 08/13] KVM: SVM: Add intercept checks for SVM instructions Joerg Roedel
2011-03-25  9:29 ` [PATCH 09/13] KVM: SVM: Add intercept checks for remaining group7 instructions Joerg Roedel
2011-03-25  9:29 ` [PATCH 10/13] KVM: SVM: Add intercept checks for remaining twobyte instructions Joerg Roedel
2011-03-25  9:29 ` [PATCH 11/13] KVM: SVM: Add intercept checks for one-byte instructions Joerg Roedel
2011-03-26  9:53   ` Avi Kivity
2011-03-25  9:29 ` [PATCH 12/13] KVM: SVM: Add checks for IO instructions Joerg Roedel
2011-03-25  9:29 ` Joerg Roedel [this message]
2011-03-26  9:55 ` [PATCH 0/13] KVM: Make the instruction emulator aware of Nested Virtualization v2 Avi Kivity
2011-03-28 10:46 [PATCH 0/13] KVM: Make the instruction emulator aware of Nested Virtualization v3 Joerg Roedel
2011-03-28 10:46 ` [PATCH 13/13] KVM: SVM: Remove nested sel_cr0_write handling code Joerg Roedel

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