[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH 2/2] target/ppc/kvm: Use KVM_CAP_PPC_AIL_MODE_3 to determine cap-
From: |
Nicholas Piggin |
Subject: |
[PATCH 2/2] target/ppc/kvm: Use KVM_CAP_PPC_AIL_MODE_3 to determine cap-ail-mode-3 support |
Date: |
Mon, 14 Feb 2022 21:17:49 +1000 |
Use KVM_CAP_PPC_AIL_MODE_3 to determine cap-ail-mode-3 support for KVM
guests. Keep the fallback heuristic for KVM hosts that pre-date this
CAP.
This is only proposed the KVM CAP has not yet been allocated. I will
ask to merge the new KVM cap when there are no objections on the QEMU
side.
not-yet-Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
hw/ppc/spapr_caps.c | 2 +-
linux-headers/linux/kvm.h | 1 +
target/ppc/kvm.c | 18 +++++++++++++++++-
target/ppc/kvm_ppc.h | 4 ++--
4 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index 5fd4a53c33..5cc80776d0 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -619,7 +619,7 @@ static void cap_ail_mode_3_apply(SpaprMachineState *spapr,
ERRP_GUARD();
if (kvm_enabled()) {
- if (!kvmppc_supports_ail_3()) {
+ if (!kvmppc_has_cap_ail_3()) {
error_setg(errp, "KVM implementation does not support
cap-ail-mode-3");
error_append_hint(errp, "Try appending -machine
cap-ail-mode-3=off\n");
return;
diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index 02c5e7b7bb..d91f578200 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -1130,6 +1130,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_BINARY_STATS_FD 203
#define KVM_CAP_EXIT_ON_EMULATION_FAILURE 204
#define KVM_CAP_ARM_MTE 205
+#define KVM_CAP_PPC_AIL_MODE_3 210
#ifdef KVM_CAP_IRQ_ROUTING
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 128bc530d4..d0d0bdaac4 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -90,6 +90,7 @@ static int cap_ppc_nested_kvm_hv;
static int cap_large_decr;
static int cap_fwnmi;
static int cap_rpt_invalidate;
+static int cap_ail_mode_3;
static uint32_t debug_inst_opcode;
@@ -154,6 +155,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
}
cap_rpt_invalidate = kvm_vm_check_extension(s, KVM_CAP_PPC_RPT_INVALIDATE);
+ cap_ail_mode_3 = kvm_vm_check_extension(s, KVM_CAP_PPC_AIL_MODE_3);
kvm_ppc_register_host_cpu_type();
return 0;
@@ -2563,10 +2565,24 @@ int kvmppc_has_cap_rpt_invalidate(void)
return cap_rpt_invalidate;
}
-int kvmppc_supports_ail_3(void)
+int kvmppc_has_cap_ail_3(void)
{
PowerPCCPUClass *pcc = kvm_ppc_get_host_cpu_class();
+ if (cap_ail_mode_3) {
+ return 1;
+ }
+
+ if (kvm_ioctl(kvm_state, KVM_CHECK_EXTENSION, KVM_CAP_PPC_AIL_MODE_3) ==
0) {
+ return 0;
+ }
+
+ /*
+ * For KVM hosts that pre-date this cap, special-case the test because
+ * the performance cost for disabling the feature unconditionally is
+ * prohibitive.
+ */
+
/*
* KVM PR only supports AIL-0
*/
diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
index d9d1c54955..efafa67b83 100644
--- a/target/ppc/kvm_ppc.h
+++ b/target/ppc/kvm_ppc.h
@@ -73,7 +73,7 @@ int kvmppc_set_cap_nested_kvm_hv(int enable);
int kvmppc_get_cap_large_decr(void);
int kvmppc_enable_cap_large_decr(PowerPCCPU *cpu, int enable);
int kvmppc_has_cap_rpt_invalidate(void);
-int kvmppc_supports_ail_3(void);
+int kvmppc_has_cap_ail_3(void);
int kvmppc_enable_hwrng(void);
int kvmppc_put_books_sregs(PowerPCCPU *cpu);
PowerPCCPUClass *kvm_ppc_get_host_cpu_class(void);
@@ -394,7 +394,7 @@ static inline int kvmppc_has_cap_rpt_invalidate(void)
return false;
}
-static inline int kvmppc_supports_ail_3(void)
+static inline int kvmppc_has_cap_ail_3(void)
{
return false;
}
--
2.23.0
Re: [PATCH 1/2] spapr: Add SPAPR_CAP_AIL_MODE_3 for AIL mode 3 support for H_SET_MODE hcall, David Gibson, 2022/02/14