From d7362c761ef55b7f665c4dff61d9e58b153ff11c Mon Sep 17 00:00:00 2001

From: Paolo Bonzini <pbonzini@redhat.com>

Date: Fri, 22 Nov 2019 11:53:39 +0000

Subject: [PATCH 06/16] target/i386: handle filtered_features in a new function

 mark_unavailable_features

RH-Author: Paolo Bonzini <pbonzini@redhat.com>

Message-id: <20191122115348.25000-7-pbonzini@redhat.com>

Patchwork-id: 92600

O-Subject: [RHEL8.2/rhel qemu-kvm PATCH 06/15] target/i386: handle filtered_features in a new function mark_unavailable_features

Bugzilla: 1689270

RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

RH-Acked-by: Eduardo Habkost <ehabkost@redhat.com>

RH-Acked-by: Maxim Levitsky <mlevitsk@redhat.com>

The next patch will add a different reason for filtering features, unrelated

to host feature support.  Extract a new function that takes care of disabling

the features and optionally reporting them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

(cherry picked from commit 245edd0cfb1481b7a0398cce45df23db50f00034)

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 target/i386/cpu.c | 87 ++++++++++++++++++++++++++++++-------------------------

 1 file changed, 48 insertions(+), 39 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c

index d0c48c2..b06ce9d 100644

--- a/target/i386/cpu.c

+++ b/target/i386/cpu.c

@@ -3121,17 +3121,41 @@ static char *feature_word_description(FeatureWordInfo *f, uint32_t bit)

     return NULL;

 }

-static void report_unavailable_features(FeatureWord w, uint32_t mask)

+static bool x86_cpu_have_filtered_features(X86CPU *cpu)

 {

+    FeatureWord w;

+

+    for (w = 0; w < FEATURE_WORDS; w++) {

+        if (cpu->filtered_features[w]) {

+            return true;

+        }

+    }

+

+    return false;

+}

+

+static void mark_unavailable_features(X86CPU *cpu, FeatureWord w, uint32_t mask,

+                                      const char *verbose_prefix)

+{

+    CPUX86State *env = &cpu->env;

     FeatureWordInfo *f = &feature_word_info[w];

     int i;

     char *feat_word_str;

+    if (!cpu->force_features) {

+        env->features[w] &= ~mask;

+    }

+    cpu->filtered_features[w] |= mask;

+

+    if (!verbose_prefix) {

+        return;

+    }

+

     for (i = 0; i < 32; ++i) {

         if ((1UL << i) & mask) {

             feat_word_str = feature_word_description(f, i);

-            warn_report("%s doesn't support requested feature: %s%s%s [bit %d]",

-                        accel_uses_host_cpuid() ? "host" : "TCG",

+            warn_report("%s: %s%s%s [bit %d]",

+                        verbose_prefix,

                         feat_word_str,

                         f->feat_names[i] ? "." : "",

                         f->feat_names[i] ? f->feat_names[i] : "", i);

@@ -3577,7 +3601,7 @@ static void x86_cpu_parse_featurestr(const char *typename, char *features,

 }

 static void x86_cpu_expand_features(X86CPU *cpu, Error **errp);

-static int x86_cpu_filter_features(X86CPU *cpu);

+static void x86_cpu_filter_features(X86CPU *cpu, bool verbose);

 /* Build a list with the name of all features on a feature word array */

 static void x86_cpu_list_feature_names(FeatureWordArray features,

@@ -3642,7 +3666,7 @@ static void x86_cpu_class_check_missing_features(X86CPUClass *xcc,

         next = &new->next;

     }

-    x86_cpu_filter_features(xc);

+    x86_cpu_filter_features(xc, false);

     x86_cpu_list_feature_names(xc->filtered_features, next);

@@ -3811,15 +3835,6 @@ static uint32_t x86_cpu_get_supported_feature_word(FeatureWord w,

     return r;

 }

-static void x86_cpu_report_filtered_features(X86CPU *cpu)

-{

-    FeatureWord w;

-

-    for (w = 0; w < FEATURE_WORDS; w++) {

-        report_unavailable_features(w, cpu->filtered_features[w]);

-    }

-}

-

 static void x86_cpu_apply_props(X86CPU *cpu, PropValue *props)

 {

     PropValue *pv;

@@ -5042,24 +5057,24 @@ out:

  *

  * Returns: 0 if all flags are supported by the host, non-zero otherwise.

  */

-static int x86_cpu_filter_features(X86CPU *cpu)

+static void x86_cpu_filter_features(X86CPU *cpu, bool verbose)

 {

     CPUX86State *env = &cpu->env;

     FeatureWord w;

-    int rv = 0;

+    const char *prefix = NULL;

+

+    if (verbose) {

+        prefix = accel_uses_host_cpuid()

+                 ? "host doesn't support requested feature"

+                 : "TCG doesn't support requested feature";

+    }

     for (w = 0; w < FEATURE_WORDS; w++) {

         uint32_t host_feat =

             x86_cpu_get_supported_feature_word(w, false);

         uint32_t requested_features = env->features[w];

-        uint32_t available_features = requested_features & host_feat;

-        if (!cpu->force_features) {

-            env->features[w] = available_features;

-        }

-        cpu->filtered_features[w] = requested_features & ~available_features;

-        if (cpu->filtered_features[w]) {

-            rv = 1;

-        }

+        uint32_t unavailable_features = requested_features & ~host_feat;

+        mark_unavailable_features(cpu, w, unavailable_features, prefix);

     }

     if ((env->features[FEAT_7_0_EBX] & CPUID_7_0_EBX_INTEL_PT) &&

@@ -5085,13 +5100,9 @@ static int x86_cpu_filter_features(X86CPU *cpu)

              * host can't emulate the capabilities we report on

              * cpu_x86_cpuid(), intel-pt can't be enabled on the current host.

              */

-            env->features[FEAT_7_0_EBX] &= ~CPUID_7_0_EBX_INTEL_PT;

-            cpu->filtered_features[FEAT_7_0_EBX] |= CPUID_7_0_EBX_INTEL_PT;

-            rv = 1;

+            mark_unavailable_features(cpu, FEAT_7_0_EBX, CPUID_7_0_EBX_INTEL_PT, prefix);

         }

     }

-

-    return rv;

 }

 static void x86_cpu_realizefn(DeviceState *dev, Error **errp)

@@ -5120,16 +5131,14 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)

         goto out;

     }

-    if (x86_cpu_filter_features(cpu) &&

-        (cpu->check_cpuid || cpu->enforce_cpuid)) {

-        x86_cpu_report_filtered_features(cpu);

-        if (cpu->enforce_cpuid) {

-            error_setg(&local_err,

-                       accel_uses_host_cpuid() ?

-                           "Host doesn't support requested features" :

-                           "TCG doesn't support requested features");

-            goto out;

-        }

+    x86_cpu_filter_features(cpu, cpu->check_cpuid || cpu->enforce_cpuid);

+

+    if (cpu->enforce_cpuid && x86_cpu_have_filtered_features(cpu)) {

+        error_setg(&local_err,

+                   accel_uses_host_cpuid() ?

+                       "Host doesn't support requested features" :

+                       "TCG doesn't support requested features");

+        goto out;

     }

     /* On AMD CPUs, some CPUID[8000_0001].EDX bits must match the bits on

-- 

1.8.3.1