[PATCH 4/8] x86/pv: handle reads to the PAT MSR

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

The value in the PAT MSR is part of the ABI between Xen and PV guests,
and there's no reason to not allow a PV guest to read it.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/pv/emul-priv-op.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/xen/arch/x86/pv/emul-priv-op.c b/xen/arch/x86/pv/emul-priv-op.c
index fd3cbfaebc..ff87c7d769 100644
--- a/xen/arch/x86/pv/emul-priv-op.c
+++ b/xen/arch/x86/pv/emul-priv-op.c
@@ -900,6 +900,10 @@ static int read_msr(unsigned int reg, uint64_t *val,
         *val = guest_efer(currd);
         return X86EMUL_OKAY;
 
+    case MSR_IA32_CR_PAT:
+        *val = XEN_MSR_PAT;
+        return X86EMUL_OKAY;
+
     case MSR_K7_FID_VID_CTL:
     case MSR_K7_FID_VID_STATUS:
     case MSR_K8_PSTATE_LIMIT:
-- 
2.28.0