Now that we have working system register sync, we push more target CPU
properties into the virtual machine. That might be useful in some
situations, but is not the typical case that users want.
So let's add a -cpu host option that allows them to explicitly pass all
CPU capabilities of their host CPU into the guest.
Signed-off-by: Alexander Graf <agraf@csgraf.de>
Acked-by: Roman Bolshakov <r.bolshakov@yadro.com>
---
include/sysemu/hvf.h | 2 ++
target/arm/cpu.c | 9 ++++++---
target/arm/cpu.h | 2 ++
target/arm/hvf/hvf.c | 41 +++++++++++++++++++++++++++++++++++++++++
target/arm/kvm_arm.h | 2 --
5 files changed, 51 insertions(+), 5 deletions(-)
diff --git a/include/sysemu/hvf.h b/include/sysemu/hvf.h
index f893768df9..7eb61cf094 100644
--- a/include/sysemu/hvf.h
+++ b/include/sysemu/hvf.h
@@ -19,6 +19,8 @@
#ifdef CONFIG_HVF
uint32_t hvf_get_supported_cpuid(uint32_t func, uint32_t idx,
int reg);
+struct ARMCPU;
+void hvf_arm_set_cpu_features_from_host(struct ARMCPU *cpu);
extern bool hvf_allowed;
#define hvf_enabled() (hvf_allowed)
#else /* !CONFIG_HVF */
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index f1929b5eba..abd129d23f 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -2288,12 +2288,16 @@ static void arm_cpu_class_init(ObjectClass *oc, void *data)
#endif
}
-#ifdef CONFIG_KVM
+#if defined(CONFIG_KVM) || defined(CONFIG_HVF)
static void arm_host_initfn(Object *obj)
{
ARMCPU *cpu = ARM_CPU(obj);
+#ifdef CONFIG_KVM
kvm_arm_set_cpu_features_from_host(cpu);
+#else
+ hvf_arm_set_cpu_features_from_host(cpu);
+#endif
if (arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) {
aarch64_add_sve_properties(obj);
}
@@ -2305,7 +2309,6 @@ static const TypeInfo host_arm_cpu_type_info = {
.parent = TYPE_AARCH64_CPU,
.instance_init = arm_host_initfn,
};
-
#endif
static void arm_cpu_instance_init(Object *obj)
@@ -2364,7 +2367,7 @@ static void arm_cpu_register_types(void)
type_register_static(&arm_cpu_type_info);
-#ifdef CONFIG_KVM
+#if defined(CONFIG_KVM) || defined(CONFIG_HVF)
type_register_static(&host_arm_cpu_type_info);
#endif
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index df0d677833..5cc59df451 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -2961,6 +2961,8 @@ bool write_cpustate_to_list(ARMCPU *cpu, bool kvm_sync);
#define ARM_CPU_TYPE_NAME(name) (name ARM_CPU_TYPE_SUFFIX)
#define CPU_RESOLVING_TYPE TYPE_ARM_CPU
+#define TYPE_ARM_HOST_CPU "host-" TYPE_ARM_CPU
+
#define cpu_signal_handler cpu_arm_signal_handler
#define cpu_list arm_cpu_list
diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index 98bd6712c0..42dcc23ba0 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -372,6 +372,47 @@ static uint64_t hvf_get_reg(CPUState *cpu, int rt)
return val;
}
+void hvf_arm_set_cpu_features_from_host(ARMCPU *cpu)
+{
+ ARMISARegisters host_isar;
+ const struct isar_regs {
+ int reg;
+ uint64_t *val;
+ } regs[] = {
+ { HV_SYS_REG_ID_AA64PFR0_EL1, &host_isar.id_aa64pfr0 },
+ { HV_SYS_REG_ID_AA64PFR1_EL1, &host_isar.id_aa64pfr1 },
+ { HV_SYS_REG_ID_AA64DFR0_EL1, &host_isar.id_aa64dfr0 },
+ { HV_SYS_REG_ID_AA64DFR1_EL1, &host_isar.id_aa64dfr1 },
+ { HV_SYS_REG_ID_AA64ISAR0_EL1, &host_isar.id_aa64isar0 },
+ { HV_SYS_REG_ID_AA64ISAR1_EL1, &host_isar.id_aa64isar1 },
+ { HV_SYS_REG_ID_AA64MMFR0_EL1, &host_isar.id_aa64mmfr0 },
+ { HV_SYS_REG_ID_AA64MMFR1_EL1, &host_isar.id_aa64mmfr1 },
+ { HV_SYS_REG_ID_AA64MMFR2_EL1, &host_isar.id_aa64mmfr2 },
+ };
+ hv_vcpu_t fd;
+ hv_vcpu_exit_t *exit;
+ int i;
+
+ cpu->dtb_compatible = "arm,arm-v8";
+ cpu->env.features = (1ULL << ARM_FEATURE_V8) |
+ (1ULL << ARM_FEATURE_NEON) |
+ (1ULL << ARM_FEATURE_AARCH64) |
+ (1ULL << ARM_FEATURE_PMU) |
+ (1ULL << ARM_FEATURE_GENERIC_TIMER);
+
+ /* We set up a small vcpu to extract host registers */
+
+ assert_hvf_ok(hv_vcpu_create(&fd, &exit, NULL));
+ for (i = 0; i < ARRAY_SIZE(regs); i++) {
+ assert_hvf_ok(hv_vcpu_get_sys_reg(fd, regs[i].reg, regs[i].val));
+ }
+ assert_hvf_ok(hv_vcpu_get_sys_reg(fd, HV_SYS_REG_MIDR_EL1, &cpu->midr));
+ assert_hvf_ok(hv_vcpu_destroy(fd));
+
+ cpu->isar = host_isar;
+ cpu->reset_sctlr = 0x00c50078;
+}
+
void hvf_arch_vcpu_destroy(CPUState *cpu)
{
}
diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h
index eb81b7059e..081727a37e 100644
--- a/target/arm/kvm_arm.h
+++ b/target/arm/kvm_arm.h
@@ -214,8 +214,6 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t *cpus_to_try,
*/
void kvm_arm_destroy_scratch_host_vcpu(int *fdarray);
-#define TYPE_ARM_HOST_CPU "host-" TYPE_ARM_CPU
-
/**
* ARMHostCPUFeatures: information about the host CPU (identified
* by asking the host kernel)
--
2.24.3 (Apple Git-128)
On Wed, 20 Jan 2021 at 22:44, Alexander Graf <agraf@csgraf.de> wrote: > > Now that we have working system register sync, we push more target CPU > properties into the virtual machine. That might be useful in some > situations, but is not the typical case that users want. > > So let's add a -cpu host option that allows them to explicitly pass all > CPU capabilities of their host CPU into the guest. > > Signed-off-by: Alexander Graf <agraf@csgraf.de> > Acked-by: Roman Bolshakov <r.bolshakov@yadro.com> > --- > include/sysemu/hvf.h | 2 ++ > target/arm/cpu.c | 9 ++++++--- > target/arm/cpu.h | 2 ++ > target/arm/hvf/hvf.c | 41 +++++++++++++++++++++++++++++++++++++++++ > target/arm/kvm_arm.h | 2 -- > 5 files changed, 51 insertions(+), 5 deletions(-) > > diff --git a/include/sysemu/hvf.h b/include/sysemu/hvf.h > index f893768df9..7eb61cf094 100644 > --- a/include/sysemu/hvf.h > +++ b/include/sysemu/hvf.h > @@ -19,6 +19,8 @@ > #ifdef CONFIG_HVF > uint32_t hvf_get_supported_cpuid(uint32_t func, uint32_t idx, > int reg); > +struct ARMCPU; Yuck. > +void hvf_arm_set_cpu_features_from_host(struct ARMCPU *cpu); This is arm-specific, it doesn't belong in the generic hvf.h. Put it somewhere else, and somewhere that we can get the typedef from cpu.h, same as with the kvm equivalent. > extern bool hvf_allowed; > #define hvf_enabled() (hvf_allowed) > #else /* !CONFIG_HVF */ > diff --git a/target/arm/cpu.c b/target/arm/cpu.c > index f1929b5eba..abd129d23f 100644 > --- a/target/arm/cpu.c > +++ b/target/arm/cpu.c > @@ -2288,12 +2288,16 @@ static void arm_cpu_class_init(ObjectClass *oc, void *data) > #endif > } > > -#ifdef CONFIG_KVM > +#if defined(CONFIG_KVM) || defined(CONFIG_HVF) > static void arm_host_initfn(Object *obj) > { > ARMCPU *cpu = ARM_CPU(obj); > > +#ifdef CONFIG_KVM > kvm_arm_set_cpu_features_from_host(cpu); > +#else > + hvf_arm_set_cpu_features_from_host(cpu); > +#endif > if (arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) { > aarch64_add_sve_properties(obj); > } This adds all the SVE related properties, so you probably need to have an equivalent of the kvm_arm_sve_supported() checks in cpu64.c that make those properties return an error on HVF. > @@ -2305,7 +2309,6 @@ static const TypeInfo host_arm_cpu_type_info = { > .parent = TYPE_AARCH64_CPU, > .instance_init = arm_host_initfn, > }; > - > #endif Stray whitespace change. > > static void arm_cpu_instance_init(Object *obj) > @@ -2364,7 +2367,7 @@ static void arm_cpu_register_types(void) > > type_register_static(&arm_cpu_type_info); > > -#ifdef CONFIG_KVM > +#if defined(CONFIG_KVM) || defined(CONFIG_HVF) > type_register_static(&host_arm_cpu_type_info); > #endif > > diff --git a/target/arm/cpu.h b/target/arm/cpu.h > index df0d677833..5cc59df451 100644 > --- a/target/arm/cpu.h > +++ b/target/arm/cpu.h > @@ -2961,6 +2961,8 @@ bool write_cpustate_to_list(ARMCPU *cpu, bool kvm_sync); > #define ARM_CPU_TYPE_NAME(name) (name ARM_CPU_TYPE_SUFFIX) > #define CPU_RESOLVING_TYPE TYPE_ARM_CPU > > +#define TYPE_ARM_HOST_CPU "host-" TYPE_ARM_CPU > + > #define cpu_signal_handler cpu_arm_signal_handler > #define cpu_list arm_cpu_list > > diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c > index 98bd6712c0..42dcc23ba0 100644 > --- a/target/arm/hvf/hvf.c > +++ b/target/arm/hvf/hvf.c > @@ -372,6 +372,47 @@ static uint64_t hvf_get_reg(CPUState *cpu, int rt) > return val; > } > > +void hvf_arm_set_cpu_features_from_host(ARMCPU *cpu) > +{ > + ARMISARegisters host_isar; > + const struct isar_regs { > + int reg; > + uint64_t *val; > + } regs[] = { > + { HV_SYS_REG_ID_AA64PFR0_EL1, &host_isar.id_aa64pfr0 }, > + { HV_SYS_REG_ID_AA64PFR1_EL1, &host_isar.id_aa64pfr1 }, > + { HV_SYS_REG_ID_AA64DFR0_EL1, &host_isar.id_aa64dfr0 }, > + { HV_SYS_REG_ID_AA64DFR1_EL1, &host_isar.id_aa64dfr1 }, > + { HV_SYS_REG_ID_AA64ISAR0_EL1, &host_isar.id_aa64isar0 }, > + { HV_SYS_REG_ID_AA64ISAR1_EL1, &host_isar.id_aa64isar1 }, > + { HV_SYS_REG_ID_AA64MMFR0_EL1, &host_isar.id_aa64mmfr0 }, > + { HV_SYS_REG_ID_AA64MMFR1_EL1, &host_isar.id_aa64mmfr1 }, > + { HV_SYS_REG_ID_AA64MMFR2_EL1, &host_isar.id_aa64mmfr2 }, > + }; Since there's no AArch32 support in this register list, we should check and error-out if the ID_AA64PFR0_EL1 value we read has 2 in either the .EL0 or .EL1 fields. (This is a never-happen case on current hardware AIUI, but we might as well be explicit about it.) > + hv_vcpu_t fd; > + hv_vcpu_exit_t *exit; > + int i; > + > + cpu->dtb_compatible = "arm,arm-v8"; > + cpu->env.features = (1ULL << ARM_FEATURE_V8) | > + (1ULL << ARM_FEATURE_NEON) | > + (1ULL << ARM_FEATURE_AARCH64) | > + (1ULL << ARM_FEATURE_PMU) | > + (1ULL << ARM_FEATURE_GENERIC_TIMER); > + > + /* We set up a small vcpu to extract host registers */ > + > + assert_hvf_ok(hv_vcpu_create(&fd, &exit, NULL)); > + for (i = 0; i < ARRAY_SIZE(regs); i++) { > + assert_hvf_ok(hv_vcpu_get_sys_reg(fd, regs[i].reg, regs[i].val)); > + } > + assert_hvf_ok(hv_vcpu_get_sys_reg(fd, HV_SYS_REG_MIDR_EL1, &cpu->midr)); > + assert_hvf_ok(hv_vcpu_destroy(fd)); Nicer to follow the KVM approach of only doing this once and caching the results in arm_host_cpu_features, so that for a many-cores VM you don't do it once per core. > + > + cpu->isar = host_isar; > + cpu->reset_sctlr = 0x00c50078; > +} > + > void hvf_arch_vcpu_destroy(CPUState *cpu) > { > } > diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h > index eb81b7059e..081727a37e 100644 > --- a/target/arm/kvm_arm.h > +++ b/target/arm/kvm_arm.h > @@ -214,8 +214,6 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t *cpus_to_try, > */ > void kvm_arm_destroy_scratch_host_vcpu(int *fdarray); > > -#define TYPE_ARM_HOST_CPU "host-" TYPE_ARM_CPU > - > /** > * ARMHostCPUFeatures: information about the host CPU (identified > * by asking the host kernel) > -- > 2.24.3 (Apple Git-128) thanks -- PMM
On 28.01.21 17:55, Peter Maydell wrote: > On Wed, 20 Jan 2021 at 22:44, Alexander Graf <agraf@csgraf.de> wrote: >> Now that we have working system register sync, we push more target CPU >> properties into the virtual machine. That might be useful in some >> situations, but is not the typical case that users want. >> >> So let's add a -cpu host option that allows them to explicitly pass all >> CPU capabilities of their host CPU into the guest. >> >> Signed-off-by: Alexander Graf <agraf@csgraf.de> >> Acked-by: Roman Bolshakov <r.bolshakov@yadro.com> >> --- >> include/sysemu/hvf.h | 2 ++ >> target/arm/cpu.c | 9 ++++++--- >> target/arm/cpu.h | 2 ++ >> target/arm/hvf/hvf.c | 41 +++++++++++++++++++++++++++++++++++++++++ >> target/arm/kvm_arm.h | 2 -- >> 5 files changed, 51 insertions(+), 5 deletions(-) >> >> diff --git a/include/sysemu/hvf.h b/include/sysemu/hvf.h >> index f893768df9..7eb61cf094 100644 >> --- a/include/sysemu/hvf.h >> +++ b/include/sysemu/hvf.h >> @@ -19,6 +19,8 @@ >> #ifdef CONFIG_HVF >> uint32_t hvf_get_supported_cpuid(uint32_t func, uint32_t idx, >> int reg); >> +struct ARMCPU; > Yuck. > [...] >> + hv_vcpu_t fd; >> + hv_vcpu_exit_t *exit; >> + int i; >> + >> + cpu->dtb_compatible = "arm,arm-v8"; >> + cpu->env.features = (1ULL << ARM_FEATURE_V8) | >> + (1ULL << ARM_FEATURE_NEON) | >> + (1ULL << ARM_FEATURE_AARCH64) | >> + (1ULL << ARM_FEATURE_PMU) | >> + (1ULL << ARM_FEATURE_GENERIC_TIMER); >> + >> + /* We set up a small vcpu to extract host registers */ >> + >> + assert_hvf_ok(hv_vcpu_create(&fd, &exit, NULL)); >> + for (i = 0; i < ARRAY_SIZE(regs); i++) { >> + assert_hvf_ok(hv_vcpu_get_sys_reg(fd, regs[i].reg, regs[i].val)); >> + } >> + assert_hvf_ok(hv_vcpu_get_sys_reg(fd, HV_SYS_REG_MIDR_EL1, &cpu->midr)); >> + assert_hvf_ok(hv_vcpu_destroy(fd)); > Nicer to follow the KVM approach of only doing this once > and caching the results in arm_host_cpu_features, so that > for a many-cores VM you don't do it once per core. I tend to disagree. This scales nicely with the number of cores you have in the system and it's blazingly fast :). I would rather like to optimize for simplicity here. The rest of the comments I agree with and will address them in v7 :) Alex
On Sun, 16 May 2021 at 12:16, Alexander Graf <agraf@csgraf.de> wrote: > > > On 28.01.21 17:55, Peter Maydell wrote: > > Nicer to follow the KVM approach of only doing this once > > and caching the results in arm_host_cpu_features, so that > > for a many-cores VM you don't do it once per core. > > > I tend to disagree. This scales nicely with the number of cores you have > in the system and it's blazingly fast :). I would rather like to > optimize for simplicity here. How does "do something once per vCPU" scale better than "do something once when QEMU starts" ?? I would prefer to optimise for "don't be unnecessarily different from how we do stuff with KVM", please. thanks -- PMM
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