linux-kernel - [PATCH 5/7] KVM: SVM: Use svm_msrpm_offset in nested_svm_exit_handled

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 1 Mar 2010 15:34:38 +0100
From:	Joerg Roedel <joerg.roedel@....com>
To:	Avi Kivity <avi@...hat.com>, Marcelo Tosatti <mtosatti@...hat.com>
CC:	Alexander Graf <agraf@...e.de>, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org, Joerg Roedel <joerg.roedel@....com>
Subject: [PATCH 5/7] KVM: SVM: Use svm_msrpm_offset in nested_svm_exit_handled_msr

There is a generic function now to calculate msrpm offsets.
Use that function in nested_svm_exit_handled_msr() remove
the duplicate logic (which had a bug anyway).

Signed-off-by: Joerg Roedel <joerg.roedel@....com>
---
 arch/x86/kvm/svm.c |   47 +++++++++++++++++------------------------------
 1 files changed, 17 insertions(+), 30 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index c04ce1e..b705115 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1654,40 +1654,27 @@ static void nested_svm_unmap(struct page *page)
 
 static int 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];
-	u32 t0, t1;
-	int ret;
-	u8 val;
+	u32 offset, msr, value;
+	int write, mask;
 
 	if (!(svm->nested.intercept & (1ULL << INTERCEPT_MSR_PROT)))
 		return NESTED_EXIT_HOST;
 
-	switch (msr) {
-	case 0 ... 0x1fff:
-		t0 = (msr * 2) % 8;
-		t1 = msr / 8;
-		break;
-	case 0xc0000000 ... 0xc0001fff:
-		t0 = (8192 + msr - 0xc0000000) * 2;
-		t1 = (t0 / 8);
-		t0 %= 8;
-		break;
-	case 0xc0010000 ... 0xc0011fff:
-		t0 = (16384 + msr - 0xc0010000) * 2;
-		t1 = (t0 / 8);
-		t0 %= 8;
-		break;
-	default:
-		ret = NESTED_EXIT_DONE;
-		goto out;
-	}
+	msr    = svm->vcpu.arch.regs[VCPU_REGS_RCX];
+	offset = svm_msrpm_offset(msr);
+	write  = svm->vmcb->control.exit_info_1 & 1;
+	mask   = 1 << ((2 * (msr & 0xf)) + write);
 
-	if (!kvm_read_guest(svm->vcpu.kvm, svm->nested.vmcb_msrpm + t1, &val, 1))
-		ret = val & ((1 << param) << t0) ? NESTED_EXIT_DONE : NESTED_EXIT_HOST;
+	if (offset == MSR_INVALID)
+		return NESTED_EXIT_DONE;
 
-out:
-	return ret;
+	/* Offset is in 32 bit units but need in 8 bit units */
+	offset *= 4;
+
+	if (kvm_read_guest(svm->vcpu.kvm, svm->nested.vmcb_msrpm + offset, &value, 4))
+		return NESTED_EXIT_DONE;
+
+	return (value & mask) ? NESTED_EXIT_DONE : NESTED_EXIT_HOST;
 }
 
 static int nested_svm_exit_special(struct vcpu_svm *svm)
@@ -1948,8 +1935,8 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
 		if (msrpm_offsets[i] == 0xffffffff)
 			break;
 
-		offset = svm->nested.vmcb_msrpm + msrpm_offsets[i];
-		p      = msrpm_offsets[i] / 4;
+		p      = msrpm_offsets[i];
+		offset = svm->nested.vmcb_msrpm + (p * 4);
 
 		if (kvm_read_guest(svm->vcpu.kvm, offset, &value, 4))
 			return false;
-- 
1.7.0


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/