From: Eduardo Habkost <ehabkost@redhat.com>
To: qemu-devel@nongnu.org, Peter Maydell <peter.maydell@linaro.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>,
kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
Richard Henderson <richard.henderson@linaro.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>
Subject: [PULL 04/11] i386: expand Hyper-V features during CPU feature expansion time
Date: Tue, 13 Jul 2021 12:09:50 -0400 [thread overview]
Message-ID: <20210713160957.3269017-5-ehabkost@redhat.com> (raw)
In-Reply-To: <20210713160957.3269017-1-ehabkost@redhat.com>
From: Vitaly Kuznetsov <vkuznets@redhat.com>
To make Hyper-V features appear in e.g. QMP query-cpu-model-expansion we
need to expand and set the corresponding CPUID leaves early. Modify
x86_cpu_get_supported_feature_word() to call newly intoduced Hyper-V
specific kvm_hv_get_supported_cpuid() instead of
kvm_arch_get_supported_cpuid(). We can't use kvm_arch_get_supported_cpuid()
as Hyper-V specific CPUID leaves intersect with KVM's.
Note, early expansion will only happen when KVM supports system wide
KVM_GET_SUPPORTED_HV_CPUID ioctl (KVM_CAP_SYS_HYPERV_CPUID).
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210608120817.1325125-6-vkuznets@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
target/i386/kvm/kvm_i386.h | 1 +
target/i386/cpu.c | 4 ++++
target/i386/kvm/kvm-stub.c | 5 +++++
target/i386/kvm/kvm.c | 24 ++++++++++++++++++++----
4 files changed, 30 insertions(+), 4 deletions(-)
diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h
index dc725083891..54667b35f09 100644
--- a/target/i386/kvm/kvm_i386.h
+++ b/target/i386/kvm/kvm_i386.h
@@ -47,6 +47,7 @@ bool kvm_has_x2apic_api(void);
bool kvm_has_waitpkg(void);
bool kvm_hv_vpindex_settable(void);
+bool kvm_hyperv_expand_features(X86CPU *cpu, Error **errp);
uint64_t kvm_swizzle_msi_ext_dest_id(uint64_t address);
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 5f595a0d7e2..46befde3876 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5974,6 +5974,10 @@ void x86_cpu_expand_features(X86CPU *cpu, Error **errp)
if (env->cpuid_xlevel2 == UINT32_MAX) {
env->cpuid_xlevel2 = env->cpuid_min_xlevel2;
}
+
+ if (kvm_enabled()) {
+ kvm_hyperv_expand_features(cpu, errp);
+ }
}
/*
diff --git a/target/i386/kvm/kvm-stub.c b/target/i386/kvm/kvm-stub.c
index 92f49121b8f..f6e7e4466e1 100644
--- a/target/i386/kvm/kvm-stub.c
+++ b/target/i386/kvm/kvm-stub.c
@@ -39,3 +39,8 @@ bool kvm_hv_vpindex_settable(void)
{
return false;
}
+
+bool kvm_hyperv_expand_features(X86CPU *cpu, Error **errp)
+{
+ abort();
+}
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index ef127762bca..556815db13d 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1220,13 +1220,22 @@ static uint32_t hv_build_cpuid_leaf(CPUState *cs, uint32_t func, int reg)
* of 'hv_passthrough' mode and fills the environment with all supported
* Hyper-V features.
*/
-static bool hyperv_expand_features(CPUState *cs, Error **errp)
+bool kvm_hyperv_expand_features(X86CPU *cpu, Error **errp)
{
- X86CPU *cpu = X86_CPU(cs);
+ CPUState *cs = CPU(cpu);
if (!hyperv_enabled(cpu))
return true;
+ /*
+ * When kvm_hyperv_expand_features is called at CPU feature expansion
+ * time per-CPU kvm_state is not available yet so we can only proceed
+ * when KVM_CAP_SYS_HYPERV_CPUID is supported.
+ */
+ if (!cs->kvm_state &&
+ !kvm_check_extension(kvm_state, KVM_CAP_SYS_HYPERV_CPUID))
+ return true;
+
if (cpu->hyperv_passthrough) {
cpu->hyperv_vendor_id[0] =
hv_cpuid_get_host(cs, HV_CPUID_VENDOR_AND_MAX_FUNCTIONS, R_EBX);
@@ -1593,8 +1602,15 @@ int kvm_arch_init_vcpu(CPUState *cs)
env->apic_bus_freq = KVM_APIC_BUS_FREQUENCY;
- /* Paravirtualization CPUIDs */
- if (!hyperv_expand_features(cs, &local_err)) {
+ /*
+ * kvm_hyperv_expand_features() is called here for the second time in case
+ * KVM_CAP_SYS_HYPERV_CPUID is not supported. While we can't possibly handle
+ * 'query-cpu-model-expansion' in this case as we don't have a KVM vCPU to
+ * check which Hyper-V enlightenments are supported and which are not, we
+ * can still proceed and check/expand Hyper-V enlightenments here so legacy
+ * behavior is preserved.
+ */
+ if (!kvm_hyperv_expand_features(cpu, &local_err)) {
error_report_err(local_err);
return -ENOSYS;
}
--
2.31.1
next prev parent reply other threads:[~2021-07-13 16:21 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 16:09 [PULL 00/11] x86 queue, 2021-07-13 Eduardo Habkost
2021-07-13 16:09 ` [PULL 01/11] i386: clarify 'hv-passthrough' behavior Eduardo Habkost
2021-07-13 16:09 ` [PULL 02/11] i386: hardcode supported eVMCS version to '1' Eduardo Habkost
2021-07-13 16:09 ` [PULL 03/11] i386: make hyperv_expand_features() return bool Eduardo Habkost
2021-07-13 16:09 ` Eduardo Habkost [this message]
2021-07-15 20:51 ` [PULL 04/11] i386: expand Hyper-V features during CPU feature expansion time Peter Maydell
2021-07-16 9:07 ` Vitaly Kuznetsov
2021-07-13 16:09 ` [PULL 05/11] i386: kill off hv_cpuid_check_and_set() Eduardo Habkost
2021-07-13 16:09 ` [PULL 06/11] i386: HV_HYPERCALL_AVAILABLE privilege bit is always needed Eduardo Habkost
2021-07-13 16:09 ` [PULL 07/11] i386: Hyper-V SynIC requires POST_MESSAGES/SIGNAL_EVENTS privileges Eduardo Habkost
2021-07-13 16:09 ` [PULL 08/11] target/i386: suppress CPUID leaves not defined by the CPU vendor Eduardo Habkost
2021-07-13 16:09 ` [PULL 09/11] target/i386: Fix cpuid level for AMD Eduardo Habkost
2021-07-13 16:09 ` [PULL 10/11] numa: Report expected initiator Eduardo Habkost
2021-07-13 16:09 ` [PULL 11/11] numa: Parse initiator= attribute before cpus= attribute Eduardo Habkost
2021-07-14 13:11 ` [PULL 00/11] x86 queue, 2021-07-13 Peter Maydell
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