Patchwork [3/3] Add svm cpuid features

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Submitter Joerg Roedel
Date Sept. 27, 2010, 1:16 p.m.
Message ID <1285593377-1754-4-git-send-email-joerg.roedel@amd.com>
Download mbox | patch
Permalink /patch/65848/
State New
Headers show

Comments

Joerg Roedel - Sept. 27, 2010, 1:16 p.m.
This patch adds the svm cpuid feature flags to the qemu
intialization path. It also adds the svm features available
on phenom to its cpu-definition and extends the host cpu
type to support all svm features KVM can provide.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
 target-i386/cpu.h   |   12 ++++++++
 target-i386/cpuid.c |   77 +++++++++++++++++++++++++++++++++++++++-----------
 target-i386/kvm.c   |    3 ++
 3 files changed, 75 insertions(+), 17 deletions(-)
Avi Kivity - Sept. 27, 2010, 2:58 p.m.
On 09/27/2010 03:16 PM, Joerg Roedel wrote:
> This patch adds the svm cpuid feature flags to the qemu
> intialization path. It also adds the svm features available
> on phenom to its cpu-definition and extends the host cpu
> type to support all svm features KVM can provide.
>

This should really be "all svm features" since we'll later mask them 
with kvm capabilities.  This way, if we later add more capabilities, we 
automatically gain support in userspace.

(or rather, all svm features that don't need save/restore support in 
userspace; I don't think any do, beyond svm itself)
Avi Kivity - Sept. 27, 2010, 3:02 p.m.
On 09/27/2010 04:58 PM, Avi Kivity wrote:
>  On 09/27/2010 03:16 PM, Joerg Roedel wrote:
>> This patch adds the svm cpuid feature flags to the qemu
>> intialization path. It also adds the svm features available
>> on phenom to its cpu-definition and extends the host cpu
>> type to support all svm features KVM can provide.
>>
>
> This should really be "all svm features" since we'll later mask them 
> with kvm capabilities.  This way, if we later add more capabilities, 
> we automatically gain support in userspace.
>
> (or rather, all svm features that don't need save/restore support in 
> userspace; I don't think any do, beyond svm itself)
>

I applied 2 and 3 (to branch uq/master).  If you want to add more svm 
features, please send a patch.  For patch 1, I'd like a review by 
someone who understands the compat code.
Joerg Roedel - Sept. 27, 2010, 3:40 p.m.
On Mon, Sep 27, 2010 at 11:02:23AM -0400, Avi Kivity wrote:
>   On 09/27/2010 04:58 PM, Avi Kivity wrote:
> >  On 09/27/2010 03:16 PM, Joerg Roedel wrote:
> >> This patch adds the svm cpuid feature flags to the qemu
> >> intialization path. It also adds the svm features available
> >> on phenom to its cpu-definition and extends the host cpu
> >> type to support all svm features KVM can provide.
> >>
> >
> > This should really be "all svm features" since we'll later mask them 
> > with kvm capabilities.  This way, if we later add more capabilities, 
> > we automatically gain support in userspace.

Yes, that is what -cpu host does with these patches applied. The
svm_features variable is set to -1 in this case and masked out later
with the KVM capabilities.

> >
> > (or rather, all svm features that don't need save/restore support in 
> > userspace; I don't think any do, beyond svm itself)
> >
> 
> I applied 2 and 3 (to branch uq/master).  If you want to add more svm 
> features, please send a patch.  For patch 1, I'd like a review by 
> someone who understands the compat code.

Great, thanks.

	Joerg
Avi Kivity - Sept. 27, 2010, 4:22 p.m.
On 09/27/2010 05:40 PM, Roedel, Joerg wrote:
> On Mon, Sep 27, 2010 at 11:02:23AM -0400, Avi Kivity wrote:
> >    On 09/27/2010 04:58 PM, Avi Kivity wrote:
> >  >   On 09/27/2010 03:16 PM, Joerg Roedel wrote:
> >  >>  This patch adds the svm cpuid feature flags to the qemu
> >  >>  intialization path. It also adds the svm features available
> >  >>  on phenom to its cpu-definition and extends the host cpu
> >  >>  type to support all svm features KVM can provide.
> >  >>
> >  >
> >  >  This should really be "all svm features" since we'll later mask them
> >  >  with kvm capabilities.  This way, if we later add more capabilities,
> >  >  we automatically gain support in userspace.
>
> Yes, that is what -cpu host does with these patches applied. The
> svm_features variable is set to -1 in this case and masked out later
> with the KVM capabilities.
>

Well, running current uq/master I get:

   has_svm: can't execute cpuid 0x8000000a
   kvm: no hardware support

?
Joerg Roedel - Sept. 28, 2010, 9:28 a.m.
On Mon, Sep 27, 2010 at 12:22:13PM -0400, Avi Kivity wrote:
>   On 09/27/2010 05:40 PM, Roedel, Joerg wrote:
> > On Mon, Sep 27, 2010 at 11:02:23AM -0400, Avi Kivity wrote:
> > >    On 09/27/2010 04:58 PM, Avi Kivity wrote:
> > >  >   On 09/27/2010 03:16 PM, Joerg Roedel wrote:
> > >  >>  This patch adds the svm cpuid feature flags to the qemu
> > >  >>  intialization path. It also adds the svm features available
> > >  >>  on phenom to its cpu-definition and extends the host cpu
> > >  >>  type to support all svm features KVM can provide.
> > >  >>
> > >  >
> > >  >  This should really be "all svm features" since we'll later mask them
> > >  >  with kvm capabilities.  This way, if we later add more capabilities,
> > >  >  we automatically gain support in userspace.
> >
> > Yes, that is what -cpu host does with these patches applied. The
> > svm_features variable is set to -1 in this case and masked out later
> > with the KVM capabilities.
> >
> 
> Well, running current uq/master I get:
> 
>    has_svm: can't execute cpuid 0x8000000a
>    kvm: no hardware support
> 
> ?

Weird, it worked here as I tested it. I had it on qemu/master and with
all three patches. But patch 1 should not make the difference. I take a
look, have you pushed the failing uq/master? What was your command line?

	Joerg
Avi Kivity - Sept. 28, 2010, 9:37 a.m.
On 09/28/2010 11:28 AM, Roedel, Joerg wrote:
> On Mon, Sep 27, 2010 at 12:22:13PM -0400, Avi Kivity wrote:
> >    On 09/27/2010 05:40 PM, Roedel, Joerg wrote:
> >  >  On Mon, Sep 27, 2010 at 11:02:23AM -0400, Avi Kivity wrote:
> >  >  >     On 09/27/2010 04:58 PM, Avi Kivity wrote:
> >  >  >   >    On 09/27/2010 03:16 PM, Joerg Roedel wrote:
> >  >  >   >>   This patch adds the svm cpuid feature flags to the qemu
> >  >  >   >>   intialization path. It also adds the svm features available
> >  >  >   >>   on phenom to its cpu-definition and extends the host cpu
> >  >  >   >>   type to support all svm features KVM can provide.
> >  >  >   >>
> >  >  >   >
> >  >  >   >   This should really be "all svm features" since we'll later mask them
> >  >  >   >   with kvm capabilities.  This way, if we later add more capabilities,
> >  >  >   >   we automatically gain support in userspace.
> >  >
> >  >  Yes, that is what -cpu host does with these patches applied. The
> >  >  svm_features variable is set to -1 in this case and masked out later
> >  >  with the KVM capabilities.
> >  >
> >
> >  Well, running current uq/master I get:
> >
> >     has_svm: can't execute cpuid 0x8000000a
> >     kvm: no hardware support
> >
> >  ?
>
> Weird, it worked here as I tested it. I had it on qemu/master and with
> all three patches. But patch 1 should not make the difference. I take a
> look, have you pushed the failing uq/master?

Yes, 8fe6a21c76.

> What was your command line?

qemu-system-x86_64 -m 2G -cpu kvm64,+svm,+npt -enable-kvm ...

Note this is qemu.git, so -enable-kvm is needed.

Patch

diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 1144d4e..77eeab1 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -405,6 +405,17 @@ 
 #define CPUID_EXT3_IBS     (1 << 10)
 #define CPUID_EXT3_SKINIT  (1 << 12)
 
+#define CPUID_SVM_NPT          (1 << 0)
+#define CPUID_SVM_LBRV         (1 << 1)
+#define CPUID_SVM_SVMLOCK      (1 << 2)
+#define CPUID_SVM_NRIPSAVE     (1 << 3)
+#define CPUID_SVM_TSCSCALE     (1 << 4)
+#define CPUID_SVM_VMCBCLEAN    (1 << 5)
+#define CPUID_SVM_FLUSHASID    (1 << 6)
+#define CPUID_SVM_DECODEASSIST (1 << 7)
+#define CPUID_SVM_PAUSEFILTER  (1 << 10)
+#define CPUID_SVM_PFTHRESHOLD  (1 << 12)
+
 #define CPUID_VENDOR_INTEL_1 0x756e6547 /* "Genu" */
 #define CPUID_VENDOR_INTEL_2 0x49656e69 /* "ineI" */
 #define CPUID_VENDOR_INTEL_3 0x6c65746e /* "ntel" */
@@ -702,6 +713,7 @@  typedef struct CPUX86State {
     uint8_t has_error_code;
     uint32_t sipi_vector;
     uint32_t cpuid_kvm_features;
+    uint32_t cpuid_svm_features;
     
     /* in order to simplify APIC support, we leave this pointer to the
        user */
diff --git a/target-i386/cpuid.c b/target-i386/cpuid.c
index 3fcf78f..0e0bf60 100644
--- a/target-i386/cpuid.c
+++ b/target-i386/cpuid.c
@@ -79,6 +79,17 @@  static const char *kvm_feature_name[] = {
     NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 };
 
+static const char *svm_feature_name[] = {
+    "npt", "lbrv", "svm_lock", "nrip_save",
+    "tsc_scale", "vmcb_clean",  "flushbyasid", "decodeassists",
+    NULL, NULL, "pause_filter", NULL,
+    "pfthreshold", NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+};
+
 /* collects per-function cpuid data
  */
 typedef struct model_features_t {
@@ -192,13 +203,15 @@  static void add_flagname_to_bitmaps(const char *flagname, uint32_t *features,
                                     uint32_t *ext_features,
                                     uint32_t *ext2_features,
                                     uint32_t *ext3_features,
-                                    uint32_t *kvm_features)
+                                    uint32_t *kvm_features,
+                                    uint32_t *svm_features)
 {
     if (!lookup_feature(features, flagname, NULL, feature_name) &&
         !lookup_feature(ext_features, flagname, NULL, ext_feature_name) &&
         !lookup_feature(ext2_features, flagname, NULL, ext2_feature_name) &&
         !lookup_feature(ext3_features, flagname, NULL, ext3_feature_name) &&
-        !lookup_feature(kvm_features, flagname, NULL, kvm_feature_name))
+        !lookup_feature(kvm_features, flagname, NULL, kvm_feature_name) &&
+        !lookup_feature(svm_features, flagname, NULL, svm_feature_name))
             fprintf(stderr, "CPU feature %s not found\n", flagname);
 }
 
@@ -210,7 +223,8 @@  typedef struct x86_def_t {
     int family;
     int model;
     int stepping;
-    uint32_t features, ext_features, ext2_features, ext3_features, kvm_features;
+    uint32_t features, ext_features, ext2_features, ext3_features;
+    uint32_t kvm_features, svm_features;
     uint32_t xlevel;
     char model_id[48];
     int vendor_override;
@@ -253,6 +267,7 @@  typedef struct x86_def_t {
           CPUID_EXT2_PDPE1GB */
 #define TCG_EXT3_FEATURES (CPUID_EXT3_LAHF_LM | CPUID_EXT3_SVM | \
           CPUID_EXT3_CR8LEG | CPUID_EXT3_ABM | CPUID_EXT3_SSE4A)
+#define TCG_SVM_FEATURES 0
 
 /* maintains list of cpu model definitions
  */
@@ -305,6 +320,7 @@  static x86_def_t builtin_x86_defs[] = {
                     CPUID_EXT3_OSVW, CPUID_EXT3_IBS */
         .ext3_features = CPUID_EXT3_LAHF_LM | CPUID_EXT3_SVM |
             CPUID_EXT3_ABM | CPUID_EXT3_SSE4A,
+        .svm_features = CPUID_SVM_NPT | CPUID_SVM_LBRV,
         .xlevel = 0x8000001A,
         .model_id = "AMD Phenom(tm) 9550 Quad-Core Processor"
     },
@@ -505,6 +521,15 @@  static int cpu_x86_fill_host(x86_def_t *x86_cpu_def)
     cpu_x86_fill_model_id(x86_cpu_def->model_id);
     x86_cpu_def->vendor_override = 0;
 
+
+    /*
+     * Every SVM feature requires emulation support in KVM - so we can't just
+     * read the host features here. KVM might even support SVM features not
+     * available on the host hardware. Just set all bits and mask out the
+     * unsupported ones later.
+     */
+    x86_cpu_def->svm_features = -1;
+
     return 0;
 }
 
@@ -560,8 +585,14 @@  static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
 
     char *s = strdup(cpu_model);
     char *featurestr, *name = strtok(s, ",");
-    uint32_t plus_features = 0, plus_ext_features = 0, plus_ext2_features = 0, plus_ext3_features = 0, plus_kvm_features = 0;
-    uint32_t minus_features = 0, minus_ext_features = 0, minus_ext2_features = 0, minus_ext3_features = 0, minus_kvm_features = 0;
+    /* Features to be added*/
+    uint32_t plus_features = 0, plus_ext_features = 0;
+    uint32_t plus_ext2_features = 0, plus_ext3_features = 0;
+    uint32_t plus_kvm_features = 0, plus_svm_features = 0;
+    /* Features to be removed */
+    uint32_t minus_features = 0, minus_ext_features = 0;
+    uint32_t minus_ext2_features = 0, minus_ext3_features = 0;
+    uint32_t minus_kvm_features = 0, minus_svm_features = 0;
     uint32_t numvalue;
 
     for (def = x86_defs; def; def = def->next)
@@ -579,16 +610,22 @@  static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
 
     add_flagname_to_bitmaps("hypervisor", &plus_features,
         &plus_ext_features, &plus_ext2_features, &plus_ext3_features,
-        &plus_kvm_features);
+        &plus_kvm_features, &plus_svm_features);
 
     featurestr = strtok(NULL, ",");
 
     while (featurestr) {
         char *val;
         if (featurestr[0] == '+') {
-            add_flagname_to_bitmaps(featurestr + 1, &plus_features, &plus_ext_features, &plus_ext2_features, &plus_ext3_features, &plus_kvm_features);
+            add_flagname_to_bitmaps(featurestr + 1, &plus_features,
+                            &plus_ext_features, &plus_ext2_features,
+                            &plus_ext3_features, &plus_kvm_features,
+                            &plus_svm_features);
         } else if (featurestr[0] == '-') {
-            add_flagname_to_bitmaps(featurestr + 1, &minus_features, &minus_ext_features, &minus_ext2_features, &minus_ext3_features, &minus_kvm_features);
+            add_flagname_to_bitmaps(featurestr + 1, &minus_features,
+                            &minus_ext_features, &minus_ext2_features,
+                            &minus_ext3_features, &minus_kvm_features,
+                            &minus_svm_features);
         } else if ((val = strchr(featurestr, '='))) {
             *val = 0; val++;
             if (!strcmp(featurestr, "family")) {
@@ -670,11 +707,13 @@  static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
     x86_cpu_def->ext2_features |= plus_ext2_features;
     x86_cpu_def->ext3_features |= plus_ext3_features;
     x86_cpu_def->kvm_features |= plus_kvm_features;
+    x86_cpu_def->svm_features |= plus_svm_features;
     x86_cpu_def->features &= ~minus_features;
     x86_cpu_def->ext_features &= ~minus_ext_features;
     x86_cpu_def->ext2_features &= ~minus_ext2_features;
     x86_cpu_def->ext3_features &= ~minus_ext3_features;
     x86_cpu_def->kvm_features &= ~minus_kvm_features;
+    x86_cpu_def->svm_features &= ~minus_svm_features;
     if (check_cpuid) {
         if (check_features_against_host(x86_cpu_def) && enforce_cpuid)
             goto error;
@@ -816,6 +855,7 @@  int cpu_x86_register (CPUX86State *env, const char *cpu_model)
     env->cpuid_ext3_features = def->ext3_features;
     env->cpuid_xlevel = def->xlevel;
     env->cpuid_kvm_features = def->kvm_features;
+    env->cpuid_svm_features = def->svm_features;
     if (!kvm_enabled()) {
         env->cpuid_features &= TCG_FEATURES;
         env->cpuid_ext_features &= TCG_EXT_FEATURES;
@@ -825,6 +865,7 @@  int cpu_x86_register (CPUX86State *env, const char *cpu_model)
 #endif
             );
         env->cpuid_ext3_features &= TCG_EXT3_FEATURES;
+        env->cpuid_svm_features &= TCG_SVM_FEATURES;
     }
     {
         const char *model_id = def->model_id;
@@ -1135,11 +1176,6 @@  void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
                 *ecx |= 1 << 1;    /* CmpLegacy bit */
             }
         }
-
-        if (kvm_enabled()) {
-            /* Nested SVM not yet supported in upstream QEMU */
-            *ecx &= ~CPUID_EXT3_SVM;
-        }
         break;
     case 0x80000002:
     case 0x80000003:
@@ -1184,10 +1220,17 @@  void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
         }
         break;
     case 0x8000000A:
-        *eax = 0x00000001; /* SVM Revision */
-        *ebx = 0x00000010; /* nr of ASIDs */
-        *ecx = 0;
-        *edx = 0; /* optional features */
+	if (env->cpuid_ext3_features & CPUID_EXT3_SVM) {
+		*eax = 0x00000001; /* SVM Revision */
+		*ebx = 0x00000010; /* nr of ASIDs */
+		*ecx = 0;
+		*edx = env->cpuid_svm_features; /* optional features */
+	} else {
+		*eax = 0;
+		*ebx = 0;
+		*ecx = 0;
+		*edx = 0;
+	}
         break;
     default:
         /* reserved values: zero */
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index a33d2fa..74e7b4f 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -192,6 +192,9 @@  int kvm_arch_init_vcpu(CPUState *env)
                                                              0, R_EDX);
     env->cpuid_ext3_features &= kvm_arch_get_supported_cpuid(env, 0x80000001,
                                                              0, R_ECX);
+    env->cpuid_svm_features  &= kvm_arch_get_supported_cpuid(env, 0x8000000A,
+                                                             0, R_EDX);
+
 
     cpuid_i = 0;