Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
---
CC: Jan Beulich <jbeul...@suse.com>
CC: Roger Pau Monné <roger....@citrix.com>
CC: Wei Liu <w...@xen.org>
CC: Boris Ostrovsky <boris.ostrov...@oracle.com>
CC: Ian Jackson <i...@xenproject.org>
For 4.15 This wants backporting to all security trees, as it is a fix to a
regression introduced in XSA-351.
Also it means that users don't need msr_relaxed=1 to unbreak Solaris guests,
which is a strict useability improvement.
---
xen/arch/x86/msr.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/xen/arch/x86/msr.c b/xen/arch/x86/msr.c
index 5927b6811b..a83a1d7fba 100644
--- a/xen/arch/x86/msr.c
+++ b/xen/arch/x86/msr.c
@@ -188,7 +188,6 @@ int guest_rdmsr(struct vcpu *v, uint32_t msr, uint64_t *val)
case MSR_TSX_CTRL:
case MSR_MCU_OPT_CTRL:
case MSR_RTIT_OUTPUT_BASE ... MSR_RTIT_ADDR_B(7):
- case MSR_RAPL_POWER_UNIT:
case MSR_PKG_POWER_LIMIT ... MSR_PKG_POWER_INFO:
case MSR_DRAM_POWER_LIMIT ... MSR_DRAM_POWER_INFO:
case MSR_PP0_POWER_LIMIT ... MSR_PP0_POLICY:
@@ -284,6 +283,18 @@ int guest_rdmsr(struct vcpu *v, uint32_t msr, uint64_t
*val)
goto gp_fault;
break;
+ case MSR_RAPL_POWER_UNIT:
+ /*
+ * This MSR is non-architectural. However, some versions of Solaris
+ * blindly reads it without a #GP guard, and some versions of
+ * turbostat crash after expecting a read of /proc/cpu/0/msr not to
+ * fail. Read as zero on Intel hardware.
+ */
+ if ( !(cp->x86_vendor & X86_VENDOR_INTEL) )
+ goto gp_fault;
+ *val = 0;
+ break;
+
/*
* These MSRs are not enumerated in CPUID. They have been around
* since the Pentium 4, and implemented by other vendors.
--
2.11.0
