If the CPU model supports topoext feature, enabled the
feature automatically if it can be supported.
Signed-off-by: Babu Moger <babu.moger@amd.com>
---
target/i386/cpu.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 4dd9a82..88bc73d 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -4763,6 +4763,33 @@ static int x86_cpu_filter_features(X86CPU *cpu)
#define IS_AMD_CPU(env) ((env)->cpuid_vendor1 == CPUID_VENDOR_AMD_1 && \
(env)->cpuid_vendor2 == CPUID_VENDOR_AMD_2 && \
(env)->cpuid_vendor3 == CPUID_VENDOR_AMD_3)
+/*
+ * Check if we can support this topology
+ * Fail if number of cores are beyond the supported config
+ * or nr_threads is more than 2
+ */
+static int topology_supports_topoext(int nr_cores, int nr_threads,
+ Error **errp)
+{
+ if (nr_cores > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)) {
+ error_setg(errp, "TOPOEXT unsupported with %d cores per socket",
+ nr_cores);
+ error_append_hint(errp, "TOPOEXT supports only up to %d cores per"
+ " socket\n",
+ (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET));
+ return false;
+ }
+
+ if (nr_threads > 2) {
+ error_setg(errp, "TOPOEXT unsupported with %d threads per core",
+ nr_threads);
+ error_append_hint(errp, "TOPOEXT supports only up to 2 threads"
+ " per core\n");
+ return false;
+ }
+ return true;
+}
+
static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
{
CPUState *cs = CPU(dev);
@@ -4953,6 +4980,19 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
qemu_init_vcpu(cs);
+ if (cpu->auto_topoext &&
+ !(env->user_features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT)) {
+ if (cs->nr_cores <= (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET) &&
+ (cs->nr_threads <= 2)) {
+ env->features[FEAT_8000_0001_ECX] |= CPUID_EXT3_TOPOEXT;
+ }
+ }
+
+ if ((env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT) &&
+ !topology_supports_topoext(cs->nr_cores, cs->nr_threads, errp)) {
+ return;
+ }
+
/* Only Intel CPUs support hyperthreading. Even though QEMU fixes this
* issue by adjusting CPUID_0000_0001_EBX and CPUID_8000_0008_ECX
* based on inputs (sockets,cores,threads), it is still better to gives
--
1.8.3.1
On Fri, Jun 08, 2018 at 06:56:20PM -0400, Babu Moger wrote:
> If the CPU model supports topoext feature, enabled the
> feature automatically if it can be supported.
>
> Signed-off-by: Babu Moger <babu.moger@amd.com>
> ---
> target/i386/cpu.c | 40 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 40 insertions(+)
>
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 4dd9a82..88bc73d 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -4763,6 +4763,33 @@ static int x86_cpu_filter_features(X86CPU *cpu)
> #define IS_AMD_CPU(env) ((env)->cpuid_vendor1 == CPUID_VENDOR_AMD_1 && \
> (env)->cpuid_vendor2 == CPUID_VENDOR_AMD_2 && \
> (env)->cpuid_vendor3 == CPUID_VENDOR_AMD_3)
> +/*
> + * Check if we can support this topology
> + * Fail if number of cores are beyond the supported config
> + * or nr_threads is more than 2
> + */
> +static int topology_supports_topoext(int nr_cores, int nr_threads,
> + Error **errp)
> +{
> + if (nr_cores > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)) {
> + error_setg(errp, "TOPOEXT unsupported with %d cores per socket",
> + nr_cores);
> + error_append_hint(errp, "TOPOEXT supports only up to %d cores per"
> + " socket\n",
> + (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET));
> + return false;
> + }
> +
> + if (nr_threads > 2) {
> + error_setg(errp, "TOPOEXT unsupported with %d threads per core",
> + nr_threads);
> + error_append_hint(errp, "TOPOEXT supports only up to 2 threads"
> + " per core\n");
> + return false;
> + }
> + return true;
> +}
> +
> static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
> {
> CPUState *cs = CPU(dev);
> @@ -4953,6 +4980,19 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
>
> qemu_init_vcpu(cs);
>
> + if (cpu->auto_topoext &&
> + !(env->user_features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT)) {
> + if (cs->nr_cores <= (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET) &&
> + (cs->nr_threads <= 2)) {
This duplicates the logic from topology_supports_topoext(). Why
not just call
topology_supports_topoext(cs->nr_cores, cs->nr_threads, NULL)
here?
> + env->features[FEAT_8000_0001_ECX] |= CPUID_EXT3_TOPOEXT;
> + }
> + }
> +
> + if ((env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT) &&
> + !topology_supports_topoext(cs->nr_cores, cs->nr_threads, errp)) {
> + return;
> + }
> +
> /* Only Intel CPUs support hyperthreading. Even though QEMU fixes this
> * issue by adjusting CPUID_0000_0001_EBX and CPUID_8000_0008_ECX
> * based on inputs (sockets,cores,threads), it is still better to gives
> --
> 1.8.3.1
>
--
Eduardo
> -----Original Message-----
> From: kvm-owner@vger.kernel.org [mailto:kvm-owner@vger.kernel.org]
> On Behalf Of Eduardo Habkost
> Sent: Monday, June 11, 2018 3:52 PM
> To: Moger, Babu <Babu.Moger@amd.com>
> Cc: mst@redhat.com; marcel.apfelbaum@gmail.com; pbonzini@redhat.com;
> rth@twiddle.net; mtosatti@redhat.com; qemu-devel@nongnu.org;
> kvm@vger.kernel.org; kash@tripleback.net; geoff@hostfission.com
> Subject: Re: [PATCH v13 4/5] i386: Verify and enable topoext feature if
> supported
>
> On Fri, Jun 08, 2018 at 06:56:20PM -0400, Babu Moger wrote:
> > If the CPU model supports topoext feature, enabled the
> > feature automatically if it can be supported.
> >
> > Signed-off-by: Babu Moger <babu.moger@amd.com>
> > ---
> > target/i386/cpu.c | 40 ++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 40 insertions(+)
> >
> > diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> > index 4dd9a82..88bc73d 100644
> > --- a/target/i386/cpu.c
> > +++ b/target/i386/cpu.c
> > @@ -4763,6 +4763,33 @@ static int x86_cpu_filter_features(X86CPU *cpu)
> > #define IS_AMD_CPU(env) ((env)->cpuid_vendor1 ==
> CPUID_VENDOR_AMD_1 && \
> > (env)->cpuid_vendor2 == CPUID_VENDOR_AMD_2 && \
> > (env)->cpuid_vendor3 == CPUID_VENDOR_AMD_3)
> > +/*
> > + * Check if we can support this topology
> > + * Fail if number of cores are beyond the supported config
> > + * or nr_threads is more than 2
> > + */
> > +static int topology_supports_topoext(int nr_cores, int nr_threads,
> > + Error **errp)
> > +{
> > + if (nr_cores > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)) {
> > + error_setg(errp, "TOPOEXT unsupported with %d cores per socket",
> > + nr_cores);
> > + error_append_hint(errp, "TOPOEXT supports only up to %d cores
> per"
> > + " socket\n",
> > + (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET));
> > + return false;
> > + }
> > +
> > + if (nr_threads > 2) {
> > + error_setg(errp, "TOPOEXT unsupported with %d threads per core",
> > + nr_threads);
> > + error_append_hint(errp, "TOPOEXT supports only up to 2 threads"
> > + " per core\n");
> > + return false;
> > + }
> > + return true;
> > +}
> > +
> > static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
> > {
> > CPUState *cs = CPU(dev);
> > @@ -4953,6 +4980,19 @@ static void x86_cpu_realizefn(DeviceState *dev,
> Error **errp)
> >
> > qemu_init_vcpu(cs);
> >
> > + if (cpu->auto_topoext &&
> > + !(env->user_features[FEAT_8000_0001_ECX] &
> CPUID_EXT3_TOPOEXT)) {
> > + if (cs->nr_cores <= (MAX_CORES_IN_NODE *
> MAX_NODES_PER_SOCKET) &&
> > + (cs->nr_threads <= 2)) {
>
> This duplicates the logic from topology_supports_topoext(). Why
> not just call
> topology_supports_topoext(cs->nr_cores, cs->nr_threads, NULL)
> here?
Ok. Will do it.
>
> > + env->features[FEAT_8000_0001_ECX] |= CPUID_EXT3_TOPOEXT;
> > + }
> > + }
> > +
> > + if ((env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT) &&
> > + !topology_supports_topoext(cs->nr_cores, cs->nr_threads, errp)) {
> > + return;
> > + }
> > +
> > /* Only Intel CPUs support hyperthreading. Even though QEMU fixes this
> > * issue by adjusting CPUID_0000_0001_EBX and CPUID_8000_0008_ECX
> > * based on inputs (sockets,cores,threads), it is still better to gives
> > --
> > 1.8.3.1
> >
>
> --
> Eduardo
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