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* [PATCH] Don't map nested_vmcb on INTERCEPT_MSR_PROT
@ 2009-09-03 14:51 Alexander Graf
  2009-09-03 16:00 ` Joerg Roedel
  2009-09-04 17:05 ` Marcelo Tosatti
  0 siblings, 2 replies; 6+ messages in thread
From: Alexander Graf @ 2009-09-03 14:51 UTC (permalink / raw)
  To: kvm; +Cc: Joerg Roedel

Thanks to Joerg's previous series of cleanups, we now have almost all
information we need to decide what to do on #VMEXIT because we get
the variables from the VMCB on VMRUN.

Unfortunately there's one piece that slipped through the conversion,
namely the MSR intercept which still tries to map the nested VMCB
to find out if MSRs are intercepted.

So let's use the cached value, removing the need for two atomic maps
(which breaks anyways) and fix an oops along the way.

CC: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

---

v1 -> v2:

  - Don't break when MSR is not intercepted
---
 arch/x86/kvm/svm.c |   15 ++++++---------
 1 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 2df9b45..a5f90c7 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1427,19 +1427,17 @@ static bool nested_svm_exit_handled_msr(struct vcpu_svm *svm)
 {
 	u32 param = svm->vmcb->control.exit_info_1 & 1;
 	u32 msr = svm->vcpu.arch.regs[VCPU_REGS_RCX];
-	struct vmcb *nested_vmcb;
 	bool ret = false;
 	u32 t0, t1;
 	u8 *msrpm;
 
-	nested_vmcb = nested_svm_map(svm, svm->nested.vmcb, KM_USER0);
-	msrpm       = nested_svm_map(svm, svm->nested.vmcb_msrpm, KM_USER1);
+	if (!(svm->nested.intercept & (1ULL << INTERCEPT_MSR_PROT)))
+		return false;
 
-	if (!nested_vmcb || !msrpm)
-		goto out;
+	msrpm = nested_svm_map(svm, svm->nested.vmcb_msrpm, KM_USER0);
 
-	if (!(nested_vmcb->control.intercept & (1ULL << INTERCEPT_MSR_PROT)))
-		return 0;
+	if (!msrpm)
+		goto out;
 
 	switch (msr) {
 	case 0 ... 0x1fff:
@@ -1464,8 +1462,7 @@ static bool nested_svm_exit_handled_msr(struct vcpu_svm *svm)
 	ret = msrpm[t1] & ((1 << param) << t0);
 
 out:
-	nested_svm_unmap(nested_vmcb, KM_USER0);
-	nested_svm_unmap(msrpm, KM_USER1);
+	nested_svm_unmap(msrpm, KM_USER0);
 
 	return ret;
 }
-- 
1.6.0.2


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH] Don't map nested_vmcb on INTERCEPT_MSR_PROT
@ 2009-09-03 14:12 Alexander Graf
  0 siblings, 0 replies; 6+ messages in thread
From: Alexander Graf @ 2009-09-03 14:12 UTC (permalink / raw)
  To: kvm; +Cc: Joerg Roedel

Thanks to Joerg's previous series of cleanups, we now have almost all
information we need to decide what to do on #VMEXIT because we get
the variables from the VMCB on VMRUN.

Unfortunately there's one piece that slipped through the conversion,
namely the MSR intercept which still tries to map the nested VMCB
to find out if MSRs are intercepted.

So let's use the cached value, removing the need for two atomic maps
(which breaks anyways) and fix an oops along the way.

CC: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/x86/kvm/svm.c |   11 ++++-------
 1 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 2df9b45..e597961 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1427,18 +1427,16 @@ static bool nested_svm_exit_handled_msr(struct vcpu_svm *svm)
 {
 	u32 param = svm->vmcb->control.exit_info_1 & 1;
 	u32 msr = svm->vcpu.arch.regs[VCPU_REGS_RCX];
-	struct vmcb *nested_vmcb;
 	bool ret = false;
 	u32 t0, t1;
 	u8 *msrpm;
 
-	nested_vmcb = nested_svm_map(svm, svm->nested.vmcb, KM_USER0);
-	msrpm       = nested_svm_map(svm, svm->nested.vmcb_msrpm, KM_USER1);
+	msrpm       = nested_svm_map(svm, svm->nested.vmcb_msrpm, KM_USER0);
 
-	if (!nested_vmcb || !msrpm)
+	if (!msrpm)
 		goto out;
 
-	if (!(nested_vmcb->control.intercept & (1ULL << INTERCEPT_MSR_PROT)))
+	if (!(svm->nested.intercept & (1ULL << INTERCEPT_MSR_PROT)))
 		return 0;
 
 	switch (msr) {
@@ -1464,8 +1462,7 @@ static bool nested_svm_exit_handled_msr(struct vcpu_svm *svm)
 	ret = msrpm[t1] & ((1 << param) << t0);
 
 out:
-	nested_svm_unmap(nested_vmcb, KM_USER0);
-	nested_svm_unmap(msrpm, KM_USER1);
+	nested_svm_unmap(msrpm, KM_USER0);
 
 	return ret;
 }
-- 
1.6.0.2


^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2009-09-05  0:30 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-09-03 14:51 [PATCH] Don't map nested_vmcb on INTERCEPT_MSR_PROT Alexander Graf
2009-09-03 16:00 ` Joerg Roedel
2009-09-04 17:05 ` Marcelo Tosatti
2009-09-04 22:59   ` Alexander Graf
2009-09-05  0:29     ` Marcelo Tosatti
  -- strict thread matches above, loose matches on Subject: below --
2009-09-03 14:12 Alexander Graf

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