[Xen-devel] [PATCH v2 2/3] x86/AMD: support further feature masking MSRs

["Jan Beulich" <JBeulich@xxxxxxxx>]

Newer AMD CPUs also allow masking CPUID leaf 6 ECX and CPUID leaf 7
sub-leaf 0 EAX and EBX.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Aravind Gopalakrishnan<aravind.gopalakrishnan@xxxxxxx>
---
v2: Adjust for new prior patch. Apply leaf 6 mask only on Fam15.

--- 2014-03-17.orig/docs/misc/xen-command-line.markdown 2014-04-04 
11:27:32.000000000 +0200
+++ 2014-03-17/docs/misc/xen-command-line.markdown      2014-03-18 
14:37:31.000000000 +0100
@@ -331,24 +331,42 @@ Indicate where the responsibility for dr
 ### cpuid\_mask\_cpu (AMD only)
 > `= fam_0f_rev_c | fam_0f_rev_d | fam_0f_rev_e | fam_0f_rev_f | fam_0f_rev_g 
 > | fam_10_rev_b | fam_10_rev_c | fam_11_rev_b`
 
-If the other **cpuid\_mask\_{,ext\_}e{c,d}x** options are fully set
-(unspecified on the command line), specify a pre-canned cpuid mask to
-mask the current processor down to appear as the specified processor.
-It is important to ensure that all hosts in a pool appear the same to
-guests to allow successful live migration.
+If the other **cpuid\_mask\_{,ext\_,thermal\_,l7s0\_}e{a,b,c,d}x**
+options are fully set (unspecified on the command line), specify a
+pre-canned cpuid mask to mask the current processor down to appear as
+the specified processor. It is important to ensure that all hosts in a
+pool appear the same to guests to allow successful live migration.
 
-### cpuid\_mask\_ ecx,edx,ext\_ecx,ext\_edx,xsave_eax
+### cpuid\_mask\_{{,ext\_}ecx,edx}
 > `= <integer>`
 
 > Default: `~0` (all bits set)
 
-These five command line parameters are used to specify cpuid masks to
+These four command line parameters are used to specify cpuid masks to
 help with cpuid levelling across a pool of hosts.  Setting a bit in
 the mask indicates that the feature should be enabled, while clearing
 a bit in the mask indicates that the feature should be disabled.  It
 is important to ensure that all hosts in a pool appear the same to
 guests to allow successful live migration.
 
+### cpuid\_mask\_xsave\_eax (Intel only)
+> `= <integer>`
+
+> Default: `~0` (all bits set)
+
+This command line parameter is also used to specify a cpuid mask to
+help with cpuid levelling across a pool of hosts.  See the description
+of the other respective options above.
+
+### cpuid\_mask\_{l7s0\_{eax,ebx},thermal\_ecx} (AMD only)
+> `= <integer>`
+
+> Default: `~0` (all bits set)
+
+These three command line parameters are also used to specify cpuid
+masks to help with cpuid levelling across a pool of hosts.  See the
+description of the other respective options above.
+
 ### cpuidle
 > `= <boolean>`
 
--- 2014-03-17.orig/xen/arch/x86/cpu/amd.c      2014-04-04 11:31:51.000000000 
+0200
+++ 2014-03-17/xen/arch/x86/cpu/amd.c   2014-04-04 11:35:31.000000000 +0200
@@ -30,9 +30,17 @@
  * "fam_10_rev_c"
  * "fam_11_rev_b"
  */
-static char opt_famrev[14];
+static char __initdata opt_famrev[14];
 string_param("cpuid_mask_cpu", opt_famrev);
 
+static unsigned int __initdata opt_cpuid_mask_l7s0_eax = ~0u;
+integer_param("cpuid_mask_l7s0_eax", opt_cpuid_mask_l7s0_eax);
+static unsigned int __initdata opt_cpuid_mask_l7s0_ebx = ~0u;
+integer_param("cpuid_mask_l7s0_ebx", opt_cpuid_mask_l7s0_ebx);
+
+static unsigned int __initdata opt_cpuid_mask_thermal_ecx = ~0u;
+integer_param("cpuid_mask_thermal_ecx", opt_cpuid_mask_thermal_ecx);
+
 /* 1 = allow, 0 = don't allow guest creation, -1 = don't allow boot */
 s8 __read_mostly opt_allow_unsafe;
 boolean_param("allow_unsafe", opt_allow_unsafe);
@@ -96,7 +104,11 @@ static void __devinit set_cpuidmask(cons
 {
        static unsigned int feat_ecx, feat_edx;
        static unsigned int extfeat_ecx, extfeat_edx;
+       static unsigned int l7s0_eax, l7s0_ebx;
+       static unsigned int thermal_ecx;
+       static bool_t skip_l7s0_eax_ebx, skip_thermal_ecx;
        static enum { not_parsed, no_mask, set_mask } status;
+       unsigned int eax, ebx, ecx, edx;
 
        if (status == no_mask)
                return;
@@ -104,7 +116,7 @@ static void __devinit set_cpuidmask(cons
        if (status == set_mask)
                goto setmask;
 
-       ASSERT((status == not_parsed) && (smp_processor_id() == 0));
+       ASSERT((status == not_parsed) && (c == &boot_cpu_data));
        status = no_mask;
 
        /* Fam11 doesn't support masking at all. */
@@ -112,11 +124,16 @@ static void __devinit set_cpuidmask(cons
                return;
 
        if (~(opt_cpuid_mask_ecx & opt_cpuid_mask_edx &
-             opt_cpuid_mask_ext_ecx & opt_cpuid_mask_ext_edx)) {
+             opt_cpuid_mask_ext_ecx & opt_cpuid_mask_ext_edx &
+             opt_cpuid_mask_l7s0_eax & opt_cpuid_mask_l7s0_ebx &
+             opt_cpuid_mask_thermal_ecx)) {
                feat_ecx = opt_cpuid_mask_ecx;
                feat_edx = opt_cpuid_mask_edx;
                extfeat_ecx = opt_cpuid_mask_ext_ecx;
                extfeat_edx = opt_cpuid_mask_ext_edx;
+               l7s0_eax = opt_cpuid_mask_l7s0_eax;
+               l7s0_ebx = opt_cpuid_mask_l7s0_ebx;
+               thermal_ecx = opt_cpuid_mask_thermal_ecx;
        } else if (*opt_famrev == '\0') {
                return;
        } else if (!strcmp(opt_famrev, "fam_0f_rev_c")) {
@@ -179,11 +196,39 @@ static void __devinit set_cpuidmask(cons
        printk("Writing CPUID extended feature mask ECX:EDX -> %08Xh:%08Xh\n", 
               extfeat_ecx, extfeat_edx);
 
+       if (c->cpuid_level >= 7)
+               cpuid_count(7, 0, &eax, &ebx, &ecx, &edx);
+       else
+               ebx = eax = 0;
+       if ((eax | ebx) && ~(l7s0_eax & l7s0_ebx)) {
+               if (l7s0_eax > eax)
+                       l7s0_eax = eax;
+               l7s0_ebx &= ebx;
+               printk("Writing CPUID leaf 7 subleaf 0 feature mask EAX:EBX -> 
%08Xh:%08Xh\n",
+                      l7s0_eax, l7s0_ebx);
+       } else
+               skip_l7s0_eax_ebx = 1;
+
+       /* Only Fam15 has the respective MSR. */
+       ecx = c->x86 == 0x15 && c->cpuid_level >= 6 ? cpuid_ecx(6) : 0;
+       if (ecx && ~thermal_ecx) {
+               thermal_ecx &= ecx;
+               printk("Writing CPUID thermal/power feature mask ECX -> 
%08Xh\n",
+                      thermal_ecx);
+       } else
+               skip_thermal_ecx = 1;
+
  setmask:
        /* AMD processors prior to family 10h required a 32-bit password */
        if (c->x86 >= 0x10) {
                wrmsr(MSR_K8_FEATURE_MASK, feat_edx, feat_ecx);
                wrmsr(MSR_K8_EXT_FEATURE_MASK, extfeat_edx, extfeat_ecx);
+               if (!skip_l7s0_eax_ebx)
+                       wrmsr(MSR_AMD_L7S0_FEATURE_MASK, l7s0_ebx, l7s0_eax);
+               if (!skip_thermal_ecx) {
+                       rdmsr(MSR_AMD_THRM_FEATURE_MASK, eax, edx);
+                       wrmsr(MSR_AMD_THRM_FEATURE_MASK, thermal_ecx, edx);
+               }
        } else {
                wrmsr_amd(MSR_K8_FEATURE_MASK, feat_edx, feat_ecx);
                wrmsr_amd(MSR_K8_EXT_FEATURE_MASK, extfeat_edx, extfeat_ecx);
--- 2014-03-17.orig/xen/include/asm-x86/msr-index.h     2014-03-10 
11:36:00.000000000 +0100
+++ 2014-03-17/xen/include/asm-x86/msr-index.h  2014-03-18 12:19:10.000000000 
+0100
@@ -192,6 +192,8 @@
 #define MSR_AMD_FAM15H_EVNTSEL5                0xc001020a
 #define MSR_AMD_FAM15H_PERFCTR5                0xc001020b
 
+#define MSR_AMD_L7S0_FEATURE_MASK      0xc0011002
+#define MSR_AMD_THRM_FEATURE_MASK      0xc0011003
 #define MSR_K8_FEATURE_MASK            0xc0011004
 #define MSR_K8_EXT_FEATURE_MASK                0xc0011005

Attachment: x86-AMD-more-feature-masks.patch
Description: Text document

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