From: Roger Pau Monne <roger.pau@citrix.com>
Date: Mon, 17 Aug 2020 15:57:53 +0000 (+0200)
Subject: x86/pv: handle reads to the PAT MSR
X-Git-Tag: archive/raspbian/4.16.0+51-g0941d6cb-1+rpi1~2^2~42^2~1758
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=ba28efb242341c35da30251943c352b6e00bf425;p=xen.git

x86/pv: handle reads to the PAT MSR

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@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/pv/emul-priv-op.c b/xen/arch/x86/pv/emul-priv-op.c
index d1d16b4806..971ba9e58c 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: