* [Qemu-devel] [PATCH 0/2] ppc/kvm: Always allow transactional memory on POWER8 KVM-HV
@ 2016-09-29 10:48 Thomas Huth
2016-09-29 10:48 ` [Qemu-devel] [PATCH 1/2] target-ppc/kvm: Add a wrapper function to check for KVM-PR Thomas Huth
2016-09-29 10:48 ` [Qemu-devel] [PATCH 2/2] target-ppc/kvm: Enable transactional memory on POWER8 with KVM-HV, too Thomas Huth
0 siblings, 2 replies; 5+ messages in thread
From: Thomas Huth @ 2016-09-29 10:48 UTC (permalink / raw)
To: David Gibson, qemu-ppc; +Cc: Alexander Graf, qemu-devel
KVM-HV also supports transactional memory on POWER8 with older
kernels that do not support the KVM_CAP_PPC_HTM extension yet.
The first patch introduces a proper function for checking whether
we're running on KVM-PR or KVM-HV, which is then used in the
second patch to check that we're running on POWER8 with KVM-HV,
so we can allow TM there, too.
Thomas Huth (2):
target-ppc/kvm: Add a wrapper function to check for KVM-PR
target-ppc/kvm: Enable transactional memory on POWER8 with KVM-HV, too
hw/ppc/spapr.c | 2 +-
target-ppc/kvm.c | 32 +++++++++++++++++++++-----------
2 files changed, 22 insertions(+), 12 deletions(-)
--
1.8.3.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Qemu-devel] [PATCH 1/2] target-ppc/kvm: Add a wrapper function to check for KVM-PR
2016-09-29 10:48 [Qemu-devel] [PATCH 0/2] ppc/kvm: Always allow transactional memory on POWER8 KVM-HV Thomas Huth
@ 2016-09-29 10:48 ` Thomas Huth
2016-09-29 23:23 ` David Gibson
2016-09-29 10:48 ` [Qemu-devel] [PATCH 2/2] target-ppc/kvm: Enable transactional memory on POWER8 with KVM-HV, too Thomas Huth
1 sibling, 1 reply; 5+ messages in thread
From: Thomas Huth @ 2016-09-29 10:48 UTC (permalink / raw)
To: David Gibson, qemu-ppc; +Cc: Alexander Graf, qemu-devel
It makes more sense if we have a proper function to check
for KVM-PR than to check for the GET_PVINFO extension all
over the place.
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
target-ppc/kvm.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index e9a9faf..dca50bc 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -102,6 +102,13 @@ static void kvm_kick_cpu(void *opaque)
qemu_cpu_kick(CPU(cpu));
}
+/* Check whether we are running with KVM-PR (instead of KVM-HV) */
+static bool kvmppc_is_pr(KVMState *ks)
+{
+ /* Assume KVM-PR if the GET_PVINFO capability is available */
+ return kvm_check_extension(ks, KVM_CAP_PPC_GET_PVINFO) != 0;
+}
+
static int kvm_ppc_register_host_cpu_type(void);
int kvm_arch_init(MachineState *ms, KVMState *s)
@@ -223,10 +230,9 @@ static void kvm_get_fallback_smmu_info(PowerPCCPU *cpu,
*
* For that to work we make a few assumptions:
*
- * - If KVM_CAP_PPC_GET_PVINFO is supported we are running "PR"
- * KVM which only supports 4K and 16M pages, but supports them
- * regardless of the backing store characteritics. We also don't
- * support 1T segments.
+ * - Check whether we are running "PR" KVM which only supports 4K
+ * and 16M pages, but supports them regardless of the backing
+ * store characteritics. We also don't support 1T segments.
*
* This is safe as if HV KVM ever supports that capability or PR
* KVM grows supports for more page/segment sizes, those versions
@@ -241,7 +247,7 @@ static void kvm_get_fallback_smmu_info(PowerPCCPU *cpu,
* implements KVM_CAP_PPC_GET_SMMU_INFO and thus doesn't hit
* this fallback.
*/
- if (kvm_check_extension(cs->kvm_state, KVM_CAP_PPC_GET_PVINFO)) {
+ if (kvmppc_is_pr(cs->kvm_state)) {
/* No flags */
info->flags = 0;
info->slb_size = 64;
@@ -2270,11 +2276,8 @@ int kvmppc_reset_htab(int shift_hint)
/* We have a kernel that predates the htab reset calls. For PR
* KVM, we need to allocate the htab ourselves, for an HV KVM of
- * this era, it has allocated a 16MB fixed size hash table
- * already. Kernels of this era have the GET_PVINFO capability
- * only on PR, so we use this hack to determine the right
- * answer */
- if (kvm_check_extension(kvm_state, KVM_CAP_PPC_GET_PVINFO)) {
+ * this era, it has allocated a 16MB fixed size hash table already. */
+ if (kvmppc_is_pr(kvm_state)) {
/* PR - tell caller to allocate htab */
return 0;
} else {
--
1.8.3.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [Qemu-devel] [PATCH 2/2] target-ppc/kvm: Enable transactional memory on POWER8 with KVM-HV, too
2016-09-29 10:48 [Qemu-devel] [PATCH 0/2] ppc/kvm: Always allow transactional memory on POWER8 KVM-HV Thomas Huth
2016-09-29 10:48 ` [Qemu-devel] [PATCH 1/2] target-ppc/kvm: Add a wrapper function to check for KVM-PR Thomas Huth
@ 2016-09-29 10:48 ` Thomas Huth
2016-09-29 23:26 ` David Gibson
1 sibling, 1 reply; 5+ messages in thread
From: Thomas Huth @ 2016-09-29 10:48 UTC (permalink / raw)
To: David Gibson, qemu-ppc; +Cc: Alexander Graf, qemu-devel
Transactional memory is also supported on POWER8 KVM-HV if the
KVM_CAP_PPC_HTM is not available in the kernel yet, so add a hack
to allow TM here, too.
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
hw/ppc/spapr.c | 2 +-
target-ppc/kvm.c | 9 ++++++++-
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index fc37145..2f4e818 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -584,7 +584,7 @@ static void spapr_populate_pa_features(CPUPPCState *env, void *fdt, int offset)
*/
pa_features[3] |= 0x20;
}
- if (kvmppc_has_cap_htm()) {
+ if (kvmppc_has_cap_htm() && pa_size > 24) {
pa_features[24] |= 0x80; /* Transactional memory support */
}
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index dca50bc..e990cb7 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -567,11 +567,18 @@ int kvm_arch_init_vcpu(CPUState *cs)
idle_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, kvm_kick_cpu, cpu);
- /* Some targets support access to KVM's guest TLB. */
switch (cenv->mmu_model) {
case POWERPC_MMU_BOOKE206:
+ /* This target supports access to KVM's guest TLB */
ret = kvm_booke206_tlb_init(cpu);
break;
+ case POWERPC_MMU_2_07:
+ if (!cap_htm && !kvmppc_is_pr(cs->kvm_state)) {
+ /* KVM-HV has transactional memory on POWER8 also without the
+ * KVM_CAP_PPC_HTM extension, so enable it here instead. */
+ cap_htm = true;
+ }
+ break;
default:
break;
}
--
1.8.3.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH 1/2] target-ppc/kvm: Add a wrapper function to check for KVM-PR
2016-09-29 10:48 ` [Qemu-devel] [PATCH 1/2] target-ppc/kvm: Add a wrapper function to check for KVM-PR Thomas Huth
@ 2016-09-29 23:23 ` David Gibson
0 siblings, 0 replies; 5+ messages in thread
From: David Gibson @ 2016-09-29 23:23 UTC (permalink / raw)
To: Thomas Huth; +Cc: qemu-ppc, Alexander Graf, qemu-devel
[-- Attachment #1: Type: text/plain, Size: 3211 bytes --]
On Thu, Sep 29, 2016 at 12:48:06PM +0200, Thomas Huth wrote:
> It makes more sense if we have a proper function to check
> for KVM-PR than to check for the GET_PVINFO extension all
> over the place.
>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
Applied to ppc-for-2.8. I expanded your comment to say this should
only be used for fallback tests, though.
> ---
> target-ppc/kvm.c | 23 +++++++++++++----------
> 1 file changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index e9a9faf..dca50bc 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -102,6 +102,13 @@ static void kvm_kick_cpu(void *opaque)
> qemu_cpu_kick(CPU(cpu));
> }
>
> +/* Check whether we are running with KVM-PR (instead of KVM-HV) */
> +static bool kvmppc_is_pr(KVMState *ks)
> +{
> + /* Assume KVM-PR if the GET_PVINFO capability is available */
> + return kvm_check_extension(ks, KVM_CAP_PPC_GET_PVINFO) != 0;
> +}
> +
> static int kvm_ppc_register_host_cpu_type(void);
>
> int kvm_arch_init(MachineState *ms, KVMState *s)
> @@ -223,10 +230,9 @@ static void kvm_get_fallback_smmu_info(PowerPCCPU *cpu,
> *
> * For that to work we make a few assumptions:
> *
> - * - If KVM_CAP_PPC_GET_PVINFO is supported we are running "PR"
> - * KVM which only supports 4K and 16M pages, but supports them
> - * regardless of the backing store characteritics. We also don't
> - * support 1T segments.
> + * - Check whether we are running "PR" KVM which only supports 4K
> + * and 16M pages, but supports them regardless of the backing
> + * store characteritics. We also don't support 1T segments.
> *
> * This is safe as if HV KVM ever supports that capability or PR
> * KVM grows supports for more page/segment sizes, those versions
> @@ -241,7 +247,7 @@ static void kvm_get_fallback_smmu_info(PowerPCCPU *cpu,
> * implements KVM_CAP_PPC_GET_SMMU_INFO and thus doesn't hit
> * this fallback.
> */
> - if (kvm_check_extension(cs->kvm_state, KVM_CAP_PPC_GET_PVINFO)) {
> + if (kvmppc_is_pr(cs->kvm_state)) {
> /* No flags */
> info->flags = 0;
> info->slb_size = 64;
> @@ -2270,11 +2276,8 @@ int kvmppc_reset_htab(int shift_hint)
>
> /* We have a kernel that predates the htab reset calls. For PR
> * KVM, we need to allocate the htab ourselves, for an HV KVM of
> - * this era, it has allocated a 16MB fixed size hash table
> - * already. Kernels of this era have the GET_PVINFO capability
> - * only on PR, so we use this hack to determine the right
> - * answer */
> - if (kvm_check_extension(kvm_state, KVM_CAP_PPC_GET_PVINFO)) {
> + * this era, it has allocated a 16MB fixed size hash table already. */
> + if (kvmppc_is_pr(kvm_state)) {
> /* PR - tell caller to allocate htab */
> return 0;
> } else {
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH 2/2] target-ppc/kvm: Enable transactional memory on POWER8 with KVM-HV, too
2016-09-29 10:48 ` [Qemu-devel] [PATCH 2/2] target-ppc/kvm: Enable transactional memory on POWER8 with KVM-HV, too Thomas Huth
@ 2016-09-29 23:26 ` David Gibson
0 siblings, 0 replies; 5+ messages in thread
From: David Gibson @ 2016-09-29 23:26 UTC (permalink / raw)
To: Thomas Huth; +Cc: qemu-ppc, Alexander Graf, qemu-devel
[-- Attachment #1: Type: text/plain, Size: 2110 bytes --]
On Thu, Sep 29, 2016 at 12:48:07PM +0200, Thomas Huth wrote:
> Transactional memory is also supported on POWER8 KVM-HV if the
> KVM_CAP_PPC_HTM is not available in the kernel yet, so add a hack
> to allow TM here, too.
>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
Applied to ppc-for-2.8.
> ---
> hw/ppc/spapr.c | 2 +-
> target-ppc/kvm.c | 9 ++++++++-
> 2 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index fc37145..2f4e818 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -584,7 +584,7 @@ static void spapr_populate_pa_features(CPUPPCState *env, void *fdt, int offset)
> */
> pa_features[3] |= 0x20;
> }
> - if (kvmppc_has_cap_htm()) {
> + if (kvmppc_has_cap_htm() && pa_size > 24) {
It looks like this is an unrelated fix to the original TM test. I'll
fold it into the original patch.
> pa_features[24] |= 0x80; /* Transactional memory support */
> }
>
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index dca50bc..e990cb7 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -567,11 +567,18 @@ int kvm_arch_init_vcpu(CPUState *cs)
>
> idle_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, kvm_kick_cpu, cpu);
>
> - /* Some targets support access to KVM's guest TLB. */
> switch (cenv->mmu_model) {
> case POWERPC_MMU_BOOKE206:
> + /* This target supports access to KVM's guest TLB */
> ret = kvm_booke206_tlb_init(cpu);
> break;
> + case POWERPC_MMU_2_07:
> + if (!cap_htm && !kvmppc_is_pr(cs->kvm_state)) {
> + /* KVM-HV has transactional memory on POWER8 also without the
> + * KVM_CAP_PPC_HTM extension, so enable it here instead. */
> + cap_htm = true;
> + }
> + break;
> default:
> break;
> }
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2016-09-29 23:37 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-09-29 10:48 [Qemu-devel] [PATCH 0/2] ppc/kvm: Always allow transactional memory on POWER8 KVM-HV Thomas Huth
2016-09-29 10:48 ` [Qemu-devel] [PATCH 1/2] target-ppc/kvm: Add a wrapper function to check for KVM-PR Thomas Huth
2016-09-29 23:23 ` David Gibson
2016-09-29 10:48 ` [Qemu-devel] [PATCH 2/2] target-ppc/kvm: Enable transactional memory on POWER8 with KVM-HV, too Thomas Huth
2016-09-29 23:26 ` David Gibson
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.