[src/trunk]: src/sys/dev/nvmm/x86 Improve emulation of MSR_IA32_ARCH_CAPABILI...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/982c6c7f50f2
branches:  trunk
changeset: 974797:982c6c7f50f2
user:      maxv <maxv%NetBSD.org@localhost>
date:      Tue Aug 11 15:27:46 2020 +0000

description:
Improve emulation of MSR_IA32_ARCH_CAPABILITIES: publish only the *_NO
bits. Initially they were the only ones there, but Intel then added other
bits we aren't interested in, and they must be filtered out.

diffstat:

 sys/dev/nvmm/x86/nvmm_x86_vmx.c |  24 ++++++++++++++++++++----
 1 files changed, 20 insertions(+), 4 deletions(-)

diffs (52 lines):

diff -r 5416720e5756 -r 982c6c7f50f2 sys/dev/nvmm/x86/nvmm_x86_vmx.c
--- a/sys/dev/nvmm/x86/nvmm_x86_vmx.c   Tue Aug 11 15:23:10 2020 +0000
+++ b/sys/dev/nvmm/x86/nvmm_x86_vmx.c   Tue Aug 11 15:27:46 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nvmm_x86_vmx.c,v 1.67 2020/08/05 15:20:09 maxv Exp $   */
+/*     $NetBSD: nvmm_x86_vmx.c,v 1.68 2020/08/11 15:27:46 maxv Exp $   */
 
 /*
  * Copyright (c) 2018-2020 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nvmm_x86_vmx.c,v 1.67 2020/08/05 15:20:09 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nvmm_x86_vmx.c,v 1.68 2020/08/11 15:27:46 maxv Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -1734,6 +1734,24 @@
                        cpudata->gprs[NVMM_X64_GPR_RDX] = (val >> 32);
                        goto handled;
                }
+               if (exit->u.rdmsr.msr == MSR_IA32_ARCH_CAPABILITIES) {
+                       u_int descs[4];
+                       if (cpuid_level < 7) {
+                               goto error;
+                       }
+                       x86_cpuid(7, descs);
+                       if (!(descs[3] & CPUID_SEF_ARCH_CAP)) {
+                               goto error;
+                       }
+                       val = rdmsr(MSR_IA32_ARCH_CAPABILITIES);
+                       val &= (IA32_ARCH_RDCL_NO |
+                           IA32_ARCH_SSB_NO |
+                           IA32_ARCH_MDS_NO |
+                           IA32_ARCH_TAA_NO);
+                       cpudata->gprs[NVMM_X64_GPR_RAX] = (val & 0xFFFFFFFF);
+                       cpudata->gprs[NVMM_X64_GPR_RDX] = (val >> 32);
+                       goto handled;
+               }
                for (i = 0; i < __arraycount(msr_ignore_list); i++) {
                        if (msr_ignore_list[i] != exit->u.rdmsr.msr)
                                continue;
@@ -2765,8 +2783,6 @@
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_FSBASE, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_GSBASE, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_TSC, true, false);
-       vmx_vcpu_msr_allow(cpudata->msrbm, MSR_IA32_ARCH_CAPABILITIES,
-           true, false);
        vmx_vmwrite(VMCS_MSR_BITMAP, (uint64_t)cpudata->msrbm_pa);
 
        /*