diff mbox

[v2,3/3] spapr: Set ibm, pa-features HTM from KVM_CAP_PPC_HTM

Message ID fb64116eb0795e0b2b0789a02b4ce8f694fc69e4.1467783317.git.sam.bobroff@au1.ibm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Sam Bobroff July 6, 2016, 5:35 a.m. UTC
Advertise HTM support in ibm, pa-features if KVM indicates support when
queried via a new capability (KVM_CAP_PPC_HTM).

If KVM returns false for the capability (which may indicate that the
host kernel doesn't support the capability itself) attempt to
determine availability using a fallback method based on KVM being
KVM-HV and HTM being available to the QEMU process.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
---
v2:

* Improve readability of HTM bit set code.
* Move the test for KVM into kvmppc_get_htm_support().

 hw/ppc/spapr.c       |  3 +++
 target-ppc/kvm.c     | 29 +++++++++++++++++++++++++++++
 target-ppc/kvm_ppc.h |  6 ++++++
 3 files changed, 38 insertions(+)

Comments

David Gibson July 7, 2016, 4:39 a.m. UTC | #1
On Wed, Jul 06, 2016 at 03:35:23PM +1000, Sam Bobroff wrote:
> Advertise HTM support in ibm, pa-features if KVM indicates support when
> queried via a new capability (KVM_CAP_PPC_HTM).
> 
> If KVM returns false for the capability (which may indicate that the
> host kernel doesn't support the capability itself) attempt to
> determine availability using a fallback method based on KVM being
> KVM-HV and HTM being available to the QEMU process.
> 
> Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
> v2:
> 
> * Improve readability of HTM bit set code.
> * Move the test for KVM into kvmppc_get_htm_support().
> 
>  hw/ppc/spapr.c       |  3 +++
>  target-ppc/kvm.c     | 29 +++++++++++++++++++++++++++++
>  target-ppc/kvm_ppc.h |  6 ++++++
>  3 files changed, 38 insertions(+)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 704aae7..843fbe7 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -712,6 +712,9 @@ static void spapr_populate_cpu_dt(CPUState *cs, void *fdt, int offset,
>      } else /* env->mmu_model == POWERPC_MMU_2_07 */ {
>          pa_features = pa_features_207;
>          pa_size = sizeof(pa_features_207);
> +        if (kvmppc_get_htm_support(env)) {
> +            pa_features[24] |= 0x80;
> +        }
>      }
>      if (env->ci_large_pages) {
>          pa_features[3] |= 0x20;
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index 884d564..9d13446 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -20,6 +20,7 @@
>  #include <sys/vfs.h>
>  
>  #include <linux/kvm.h>
> +#include "elf.h"
>  
>  #include "qemu-common.h"
>  #include "qemu/error-report.h"
> @@ -1976,6 +1977,34 @@ uint32_t kvmppc_get_dfp(void)
>      return kvmppc_read_int_cpu_dt("ibm,dfp");
>  }
>  
> +bool kvmppc_get_htm_support(CPUPPCState *env)
> +{
> +    PowerPCCPU *cpu = ppc_env_get_cpu(env);
> +    CPUState *cs = CPU(cpu);
> +
> +    if (!kvm_enabled()) {
> +        return false;
> +    }
> +    if (kvm_vm_check_extension(cs->kvm_state, KVM_CAP_PPC_HTM)) {
> +        return true;
> +    }
> +    /*
> +     * Fallback test for host kernels that don't yet support KVM_CAP_PPC_HTM.
> +     * This will be unnecessary when KVM_API_VERSION is incremented (to 13 or
> +     * above) because that will remove the ambiguity between the host kernel
> +     * lacking support for KVM_CAP_PPC_HTM and it having support but reporting
> +     * HTM as unavailable (both of which return 0, above).
> +     */
> +    if (kvm_vm_check_extension(cs->kvm_state, KVM_CAP_PPC_GET_PVINFO)) {
> +        /* Assume this means PR KVM, so no TM. */
> +        return false;
> +    } else {
> +        /* Assume this means HV KVM, propagate whatever host userspace sees. */
> +        unsigned long hwcap2 = qemu_getauxval(AT_HWCAP2);
> +        return !!(hwcap2 & PPC_FEATURE2_HAS_HTM);
> +    }
> +}
> +
>  static int kvmppc_get_pvinfo(CPUPPCState *env, struct kvm_ppc_pvinfo *pvinfo)
>   {
>       PowerPCCPU *cpu = ppc_env_get_cpu(env);
> diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h
> index 20bfb59..b01c717 100644
> --- a/target-ppc/kvm_ppc.h
> +++ b/target-ppc/kvm_ppc.h
> @@ -17,6 +17,7 @@ uint32_t kvmppc_get_tbfreq(void);
>  uint64_t kvmppc_get_clockfreq(void);
>  uint32_t kvmppc_get_vmx(void);
>  uint32_t kvmppc_get_dfp(void);
> +bool kvmppc_get_htm_support(CPUPPCState *env);
>  bool kvmppc_get_host_model(char **buf);
>  bool kvmppc_get_host_serial(char **buf);
>  int kvmppc_get_hasidle(CPUPPCState *env);
> @@ -90,6 +91,11 @@ static inline uint32_t kvmppc_get_dfp(void)
>      return 0;
>  }
>  
> +static inline bool kvmppc_get_htm_support(KVMState *kvm_state)
> +{
> +    return false;
> +}
> +
>  static inline int kvmppc_get_hasidle(CPUPPCState *env)
>  {
>      return 0;
diff mbox

Patch

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 704aae7..843fbe7 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -712,6 +712,9 @@  static void spapr_populate_cpu_dt(CPUState *cs, void *fdt, int offset,
     } else /* env->mmu_model == POWERPC_MMU_2_07 */ {
         pa_features = pa_features_207;
         pa_size = sizeof(pa_features_207);
+        if (kvmppc_get_htm_support(env)) {
+            pa_features[24] |= 0x80;
+        }
     }
     if (env->ci_large_pages) {
         pa_features[3] |= 0x20;
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index 884d564..9d13446 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -20,6 +20,7 @@ 
 #include <sys/vfs.h>
 
 #include <linux/kvm.h>
+#include "elf.h"
 
 #include "qemu-common.h"
 #include "qemu/error-report.h"
@@ -1976,6 +1977,34 @@  uint32_t kvmppc_get_dfp(void)
     return kvmppc_read_int_cpu_dt("ibm,dfp");
 }
 
+bool kvmppc_get_htm_support(CPUPPCState *env)
+{
+    PowerPCCPU *cpu = ppc_env_get_cpu(env);
+    CPUState *cs = CPU(cpu);
+
+    if (!kvm_enabled()) {
+        return false;
+    }
+    if (kvm_vm_check_extension(cs->kvm_state, KVM_CAP_PPC_HTM)) {
+        return true;
+    }
+    /*
+     * Fallback test for host kernels that don't yet support KVM_CAP_PPC_HTM.
+     * This will be unnecessary when KVM_API_VERSION is incremented (to 13 or
+     * above) because that will remove the ambiguity between the host kernel
+     * lacking support for KVM_CAP_PPC_HTM and it having support but reporting
+     * HTM as unavailable (both of which return 0, above).
+     */
+    if (kvm_vm_check_extension(cs->kvm_state, KVM_CAP_PPC_GET_PVINFO)) {
+        /* Assume this means PR KVM, so no TM. */
+        return false;
+    } else {
+        /* Assume this means HV KVM, propagate whatever host userspace sees. */
+        unsigned long hwcap2 = qemu_getauxval(AT_HWCAP2);
+        return !!(hwcap2 & PPC_FEATURE2_HAS_HTM);
+    }
+}
+
 static int kvmppc_get_pvinfo(CPUPPCState *env, struct kvm_ppc_pvinfo *pvinfo)
  {
      PowerPCCPU *cpu = ppc_env_get_cpu(env);
diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h
index 20bfb59..b01c717 100644
--- a/target-ppc/kvm_ppc.h
+++ b/target-ppc/kvm_ppc.h
@@ -17,6 +17,7 @@  uint32_t kvmppc_get_tbfreq(void);
 uint64_t kvmppc_get_clockfreq(void);
 uint32_t kvmppc_get_vmx(void);
 uint32_t kvmppc_get_dfp(void);
+bool kvmppc_get_htm_support(CPUPPCState *env);
 bool kvmppc_get_host_model(char **buf);
 bool kvmppc_get_host_serial(char **buf);
 int kvmppc_get_hasidle(CPUPPCState *env);
@@ -90,6 +91,11 @@  static inline uint32_t kvmppc_get_dfp(void)
     return 0;
 }
 
+static inline bool kvmppc_get_htm_support(KVMState *kvm_state)
+{
+    return false;
+}
+
 static inline int kvmppc_get_hasidle(CPUPPCState *env)
 {
     return 0;