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@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 17 insertions, 30 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 45a287e51e18..7cb2eb906eca 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1660,40 +1660,27 @@ 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)
@@ -1954,8 +1941,8 @@ 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;