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[PATCH] spapr: avoid overhead of finding vhyp class in critical operatio
From: |
Nicholas Piggin |
Subject: |
[PATCH] spapr: avoid overhead of finding vhyp class in critical operations |
Date: |
Sat, 24 Feb 2024 17:33:59 +1000 |
PPC_VIRTUAL_HYPERVISOR_GET_CLASS is used in critical operations like
interrupts and TLB misses and is quite costly. Running the
kvm-unit-tests sieve program with radix MMU enabled thrashes the TCG
TLB and spends a lot of time in TLB and page table walking code. The
test takes 67 seconds to complete with a lot of time being spent in
code related to finding the vhyp class:
12.01% [.] g_str_hash
8.94% [.] g_hash_table_lookup
8.06% [.] object_class_dynamic_cast
6.21% [.] address_space_ldq
4.94% [.] __strcmp_avx2
4.28% [.] tlb_set_page_full
4.08% [.] address_space_translate_internal
3.17% [.] object_class_dynamic_cast_assert
2.84% [.] ppc_radix64_xlate
Keep a pointer to the class and avoid this lookup. This reduces the
execution time to 40 seconds.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
This feels a bit ugly, but the performance problem of looking up the
class in fast paths can't be ignored. Is there a "nicer" way to get the
same result?
Thanks,
Nick
target/ppc/cpu.h | 3 ++-
target/ppc/mmu-book3s-v3.h | 4 +---
hw/ppc/pegasos2.c | 1 +
target/ppc/cpu_init.c | 9 +++------
target/ppc/excp_helper.c | 16 ++++------------
target/ppc/kvm.c | 4 +---
target/ppc/mmu-hash64.c | 16 ++++------------
target/ppc/mmu-radix64.c | 4 +---
8 files changed, 17 insertions(+), 40 deletions(-)
diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index ec14574d14..eb85d9aa71 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -1437,6 +1437,7 @@ struct ArchCPU {
int vcpu_id;
uint32_t compat_pvr;
PPCVirtualHypervisor *vhyp;
+ PPCVirtualHypervisorClass *vhyp_class;
void *machine_data;
int32_t node_id; /* NUMA node this CPU belongs to */
PPCHash64Options *hash64_opts;
@@ -1535,7 +1536,7 @@ DECLARE_OBJ_CHECKERS(PPCVirtualHypervisor,
PPCVirtualHypervisorClass,
static inline bool vhyp_cpu_in_nested(PowerPCCPU *cpu)
{
- return PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp)->cpu_in_nested(cpu);
+ return cpu->vhyp_class->cpu_in_nested(cpu);
}
#endif /* CONFIG_USER_ONLY */
diff --git a/target/ppc/mmu-book3s-v3.h b/target/ppc/mmu-book3s-v3.h
index 674377a19e..f3f7993958 100644
--- a/target/ppc/mmu-book3s-v3.h
+++ b/target/ppc/mmu-book3s-v3.h
@@ -108,9 +108,7 @@ static inline hwaddr ppc_hash64_hpt_mask(PowerPCCPU *cpu)
uint64_t base;
if (cpu->vhyp) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- return vhc->hpt_mask(cpu->vhyp);
+ return cpu->vhyp_class->hpt_mask(cpu->vhyp);
}
if (cpu->env.mmu_model == POWERPC_MMU_3_00) {
ppc_v3_pate_t pate;
diff --git a/hw/ppc/pegasos2.c b/hw/ppc/pegasos2.c
index 04d6decb2b..c22e8b336d 100644
--- a/hw/ppc/pegasos2.c
+++ b/hw/ppc/pegasos2.c
@@ -400,6 +400,7 @@ static void pegasos2_machine_reset(MachineState *machine,
ShutdownCause reason)
machine->fdt = fdt;
pm->cpu->vhyp = PPC_VIRTUAL_HYPERVISOR(machine);
+ pm->cpu->vhyp_class = PPC_VIRTUAL_HYPERVISOR_GET_CLASS(pm->cpu->vhyp);
}
enum pegasos2_rtas_tokens {
diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index 9bccddb350..63d0094024 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -6631,6 +6631,7 @@ void cpu_ppc_set_vhyp(PowerPCCPU *cpu,
PPCVirtualHypervisor *vhyp)
CPUPPCState *env = &cpu->env;
cpu->vhyp = vhyp;
+ cpu->vhyp_class = PPC_VIRTUAL_HYPERVISOR_GET_CLASS(vhyp);
/*
* With a virtual hypervisor mode we never allow the CPU to go
@@ -7224,9 +7225,7 @@ static void ppc_cpu_exec_enter(CPUState *cs)
PowerPCCPU *cpu = POWERPC_CPU(cs);
if (cpu->vhyp) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- vhc->cpu_exec_enter(cpu->vhyp, cpu);
+ cpu->vhyp_class->cpu_exec_enter(cpu->vhyp, cpu);
}
}
@@ -7235,9 +7234,7 @@ static void ppc_cpu_exec_exit(CPUState *cs)
PowerPCCPU *cpu = POWERPC_CPU(cs);
if (cpu->vhyp) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- vhc->cpu_exec_exit(cpu->vhyp, cpu);
+ cpu->vhyp_class->cpu_exec_exit(cpu->vhyp, cpu);
}
}
#endif /* CONFIG_TCG */
diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index 98952de267..445350488c 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -840,9 +840,7 @@ static void powerpc_excp_7xx(PowerPCCPU *cpu, int excp)
* HV mode, we need to keep hypercall support.
*/
if (lev == 1 && cpu->vhyp) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- vhc->hypercall(cpu->vhyp, cpu);
+ cpu->vhyp_class->hypercall(cpu->vhyp, cpu);
powerpc_reset_excp_state(cpu);
return;
}
@@ -1012,9 +1010,7 @@ static void powerpc_excp_74xx(PowerPCCPU *cpu, int excp)
* HV mode, we need to keep hypercall support.
*/
if (lev == 1 && cpu->vhyp) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- vhc->hypercall(cpu->vhyp, cpu);
+ cpu->vhyp_class->hypercall(cpu->vhyp, cpu);
powerpc_reset_excp_state(cpu);
return;
}
@@ -1534,9 +1530,7 @@ static void powerpc_excp_books(PowerPCCPU *cpu, int excp)
/* "PAPR mode" built-in hypercall emulation */
if (lev == 1 && books_vhyp_handles_hcall(cpu)) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- vhc->hypercall(cpu->vhyp, cpu);
+ cpu->vhyp_class->hypercall(cpu->vhyp, cpu);
powerpc_reset_excp_state(cpu);
return;
}
@@ -1677,10 +1671,8 @@ static void powerpc_excp_books(PowerPCCPU *cpu, int excp)
}
if ((new_msr & MSR_HVB) && books_vhyp_handles_hv_excp(cpu)) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
/* Deliver interrupt to L1 by returning from the H_ENTER_NESTED call */
- vhc->deliver_hv_excp(cpu, excp);
+ cpu->vhyp_class->deliver_hv_excp(cpu, excp);
powerpc_reset_excp_state(cpu);
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 26fa9d0575..5b5b96ab6b 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -862,9 +862,7 @@ int kvmppc_put_books_sregs(PowerPCCPU *cpu)
sregs.pvr = env->spr[SPR_PVR];
if (cpu->vhyp) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- sregs.u.s.sdr1 = vhc->encode_hpt_for_kvm_pr(cpu->vhyp);
+ sregs.u.s.sdr1 = cpu->vhyp_class->encode_hpt_for_kvm_pr(cpu->vhyp);
} else {
sregs.u.s.sdr1 = env->spr[SPR_SDR1];
}
diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
index d645c0bb94..196b4b2a48 100644
--- a/target/ppc/mmu-hash64.c
+++ b/target/ppc/mmu-hash64.c
@@ -516,9 +516,7 @@ const ppc_hash_pte64_t *ppc_hash64_map_hptes(PowerPCCPU
*cpu,
const ppc_hash_pte64_t *hptes;
if (cpu->vhyp) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- return vhc->map_hptes(cpu->vhyp, ptex, n);
+ return cpu->vhyp_class->map_hptes(cpu->vhyp, ptex, n);
}
base = ppc_hash64_hpt_base(cpu);
@@ -538,9 +536,7 @@ void ppc_hash64_unmap_hptes(PowerPCCPU *cpu, const
ppc_hash_pte64_t *hptes,
hwaddr ptex, int n)
{
if (cpu->vhyp) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- vhc->unmap_hptes(cpu->vhyp, hptes, ptex, n);
+ cpu->vhyp_class->unmap_hptes(cpu->vhyp, hptes, ptex, n);
return;
}
@@ -820,9 +816,7 @@ static void ppc_hash64_set_r(PowerPCCPU *cpu, hwaddr ptex,
uint64_t pte1)
hwaddr base, offset = ptex * HASH_PTE_SIZE_64 + HPTE64_DW1_R;
if (cpu->vhyp) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- vhc->hpte_set_r(cpu->vhyp, ptex, pte1);
+ cpu->vhyp_class->hpte_set_r(cpu->vhyp, ptex, pte1);
return;
}
base = ppc_hash64_hpt_base(cpu);
@@ -837,9 +831,7 @@ static void ppc_hash64_set_c(PowerPCCPU *cpu, hwaddr ptex,
uint64_t pte1)
hwaddr base, offset = ptex * HASH_PTE_SIZE_64 + HPTE64_DW1_C;
if (cpu->vhyp) {
- PPCVirtualHypervisorClass *vhc =
- PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- vhc->hpte_set_c(cpu->vhyp, ptex, pte1);
+ cpu->vhyp_class->hpte_set_c(cpu->vhyp, ptex, pte1);
return;
}
base = ppc_hash64_hpt_base(cpu);
diff --git a/target/ppc/mmu-radix64.c b/target/ppc/mmu-radix64.c
index 5823e039e6..496ba87a95 100644
--- a/target/ppc/mmu-radix64.c
+++ b/target/ppc/mmu-radix64.c
@@ -677,9 +677,7 @@ static bool ppc_radix64_xlate_impl(PowerPCCPU *cpu, vaddr
eaddr,
/* Get Partition Table */
if (cpu->vhyp) {
- PPCVirtualHypervisorClass *vhc;
- vhc = PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
- if (!vhc->get_pate(cpu->vhyp, cpu, lpid, &pate)) {
+ if (!cpu->vhyp_class->get_pate(cpu->vhyp, cpu, lpid, &pate)) {
if (guest_visible) {
ppc_radix64_raise_hsi(cpu, access_type, eaddr, eaddr,
DSISR_R_BADCONFIG);
--
2.42.0
- [PATCH] spapr: avoid overhead of finding vhyp class in critical operations,
Nicholas Piggin <=