File 5a6b36cd-3-x86-migrate-MSR_SPEC_CTRL.patch of Package xen

Overview Repositories Revisions Requests Users Attributes Meta

File 5a6b36cd-3-x86-migrate-MSR_SPEC_CTRL.patch of Package xen (Revision c31eb5bc91ad30fa0e6b5269b524d639)

Currently displaying revision c31eb5bc91ad30fa0e6b5269b524d639 , Show latest

# Commit 0cf2a4eb769302b7d7d7835540e7b2f15006df30
# Date 2018-01-26 14:10:21 +0000
# Author Andrew Cooper <andrew.cooper3@citrix.com>
# Committer Andrew Cooper <andrew.cooper3@citrix.com>
x86/migrate: Move MSR_SPEC_CTRL on migrate

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -1338,6 +1338,19 @@ long arch_do_domctl(
                     ++i;
                 }
 
+                if ( d->arch.cpuid->feat.ibrsb && v->arch.spec_ctrl )
+                {
+                    if ( i < vmsrs->msr_count && !ret )
+                    {
+                        msr.index = MSR_SPEC_CTRL;
+                        msr.reserved = 0;
+                        msr.value = v->arch.spec_ctrl;
+                        if ( copy_to_guest_offset(vmsrs->msrs, i, &msr, 1) )
+                            ret = -EFAULT;
+                    }
+                    ++i;
+                }
+
                 vcpu_unpause(v);
 
                 if ( i > vmsrs->msr_count && !ret )
@@ -1365,6 +1378,20 @@ long arch_do_domctl(
 
                 switch ( msr.index )
                 {
+                case MSR_SPEC_CTRL:
+                    if ( !d->arch.cpuid->feat.ibrsb )
+                        break; /* MSR available? */
+
+                    /*
+                     * Note: SPEC_CTRL_STIBP is specified as safe to use (i.e.
+                     * ignored) when STIBP isn't enumerated in hardware.
+                     */
+
+                    if ( msr.value & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP) )
+                        break;
+                    v->arch.spec_ctrl = msr.value;
+                    continue;
+
                 case MSR_INTEL_MISC_FEATURES_ENABLES:
                     v->arch.cpuid_faulting = !!(msr.value &
                                                 MSR_MISC_FEATURES_CPUID_FAULTING);
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -898,6 +898,7 @@ static int vmx_load_vmcs_ctxt(struct vcp
 static unsigned int __init vmx_init_msr(void)
 {
     return 1 /* MISC_FEATURES_ENABLES */ +
+           !!boot_cpu_has(X86_FEATURE_IBRSB) +
            (cpu_has_mpx && cpu_has_vmx_mpx) +
            (cpu_has_xsaves && cpu_has_vmx_xsaves);
 }
@@ -912,6 +913,12 @@ static void vmx_save_msr(struct vcpu *v,
         ctxt->msr[ctxt->count++].val = MSR_MISC_FEATURES_CPUID_FAULTING;
     }
 
+    if ( v->domain->arch.cpuid->feat.ibrsb && v->arch.spec_ctrl )
+    {
+        ctxt->msr[ctxt->count].index = MSR_SPEC_CTRL;
+        ctxt->msr[ctxt->count++].val = v->arch.spec_ctrl;
+    }
+
     if ( cpu_has_mpx && cpu_has_vmx_mpx )
     {
         __vmread(GUEST_BNDCFGS, &ctxt->msr[ctxt->count].val);
@@ -940,6 +947,19 @@ static int vmx_load_msr(struct vcpu *v,
     {
         switch ( ctxt->msr[i].index )
         {
+        case MSR_SPEC_CTRL:
+            if ( !v->domain->arch.cpuid->feat.ibrsb )
+                err = -ENXIO; /* MSR available? */
+            /*
+             * Note: SPEC_CTRL_STIBP is specified as safe to use (i.e.
+             * ignored) when STIBP isn't enumerated in hardware.
+             */
+            else if ( ctxt->msr[i].val &
+                      ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP) )
+                err = -ENXIO;
+            else
+                v->arch.spec_ctrl = ctxt->msr[i].val;
+            break;
         case MSR_INTEL_MISC_FEATURES_ENABLES:
             v->arch.cpuid_faulting = !!(ctxt->msr[i].val &
                                         MSR_MISC_FEATURES_CPUID_FAULTING);

Places

File 5a6b36cd-3-x86-migrate-MSR_SPEC_CTRL.patch of Package xen (Revision c31eb5bc91ad30fa0e6b5269b524d639)

Places