From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
Marc Zyngier <maz@kernel.org>,
Huacai Chen <chenhuacai@kernel.org>,
Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>,
Anup Patel <anup@brainfault.org>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Matthew Rosato <mjrosato@linux.ibm.com>,
Eric Farman <farman@linux.ibm.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
David Woodhouse <dwmw2@infradead.org>,
Paul Durrant <paul@xen.org>
Cc: kvm@vger.kernel.org, "David Hildenbrand" <david@redhat.com>,
"Atish Patra" <atishp@atishpatra.org>,
linux-kernel@vger.kernel.org, "Kai Huang" <kai.huang@intel.com>,
linux-riscv@lists.infradead.org, kvmarm@lists.cs.columbia.edu,
linux-s390@vger.kernel.org, "Chao Gao" <chao.gao@intel.com>,
"Suzuki K Poulose" <suzuki.poulose@arm.com>,
"Yuan Yao" <yuan.yao@intel.com>,
kvmarm@lists.linux.dev, "Thomas Gleixner" <tglx@linutronix.de>,
"Alexandru Elisei" <alexandru.elisei@arm.com>,
linux-arm-kernel@lists.infradead.org,
"Isaku Yamahata" <isaku.yamahata@intel.com>,
"Philippe Mathieu-Daudé" <philmd@linaro.org>,
"Fabiano Rosas" <farosas@linux.ibm.com>,
"Cornelia Huck" <cohuck@redhat.com>,
linux-mips@vger.kernel.org,
"Oliver Upton" <oliver.upton@linux.dev>,
"James Morse" <james.morse@arm.com>,
kvm-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v2 36/50] KVM: x86: Do VMX/SVM support checks directly in vendor code
Date: Wed, 30 Nov 2022 23:09:20 +0000 [thread overview]
Message-ID: <20221130230934.1014142-37-seanjc@google.com> (raw)
In-Reply-To: <20221130230934.1014142-1-seanjc@google.com>
Do basic VMX/SVM support checks directly in vendor code instead of
implementing them via kvm_x86_ops hooks. Beyond the superficial benefit
of providing common messages, which isn't even clearly a net positive
since vendor code can provide more precise/detailed messages, there's
zero advantage to bouncing through common x86 code.
Consolidating the checks will also simplify performing the checks
across all CPUs (in a future patch).
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/include/asm/kvm_host.h | 2 --
arch/x86/kvm/svm/svm.c | 38 +++++++++++++++------------------
arch/x86/kvm/vmx/vmx.c | 37 +++++++++++++++++---------------
arch/x86/kvm/x86.c | 11 ----------
4 files changed, 37 insertions(+), 51 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 04a9ae66fb8d..d79aedf70908 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1729,8 +1729,6 @@ struct kvm_x86_nested_ops {
};
struct kvm_x86_init_ops {
- int (*cpu_has_kvm_support)(void);
- int (*disabled_by_bios)(void);
int (*check_processor_compatibility)(void);
int (*hardware_setup)(void);
unsigned int (*handle_intel_pt_intr)(void);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index ab53da3fbcd1..49ccef9fae81 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -519,21 +519,28 @@ static void svm_init_osvw(struct kvm_vcpu *vcpu)
vcpu->arch.osvw.status |= 1;
}
-static int has_svm(void)
+static bool kvm_is_svm_supported(void)
{
const char *msg;
+ u64 vm_cr;
if (!cpu_has_svm(&msg)) {
- printk(KERN_INFO "has_svm: %s\n", msg);
- return 0;
+ pr_err("SVM not supported, %s\n", msg);
+ return false;
}
if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
pr_info("KVM is unsupported when running as an SEV guest\n");
- return 0;
+ return false;
}
- return 1;
+ rdmsrl(MSR_VM_CR, vm_cr);
+ if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE)) {
+ pr_err("SVM disabled (by BIOS) in MSR_VM_CR\n");
+ return false;
+ }
+
+ return true;
}
void __svm_write_tsc_multiplier(u64 multiplier)
@@ -572,10 +579,9 @@ static int svm_hardware_enable(void)
if (efer & EFER_SVME)
return -EBUSY;
- if (!has_svm()) {
- pr_err("%s: err EOPNOTSUPP on %d\n", __func__, me);
+ if (!kvm_is_svm_supported())
return -EINVAL;
- }
+
sd = per_cpu_ptr(&svm_data, me);
sd->asid_generation = 1;
sd->max_asid = cpuid_ebx(SVM_CPUID_FUNC) - 1;
@@ -4070,17 +4076,6 @@ static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
vmcb_mark_dirty(svm->vmcb, VMCB_CR);
}
-static int is_disabled(void)
-{
- u64 vm_cr;
-
- rdmsrl(MSR_VM_CR, vm_cr);
- if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE))
- return 1;
-
- return 0;
-}
-
static void
svm_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall)
{
@@ -5080,8 +5075,6 @@ static __init int svm_hardware_setup(void)
static struct kvm_x86_init_ops svm_init_ops __initdata = {
- .cpu_has_kvm_support = has_svm,
- .disabled_by_bios = is_disabled,
.hardware_setup = svm_hardware_setup,
.check_processor_compatibility = svm_check_processor_compat,
@@ -5095,6 +5088,9 @@ static int __init svm_init(void)
__unused_size_checks();
+ if (!kvm_is_svm_supported())
+ return -EOPNOTSUPP;
+
r = kvm_x86_vendor_init(&svm_init_ops);
if (r)
return r;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 3f7d9f88b314..23b64bf4bfcf 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2485,17 +2485,6 @@ static void vmx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
}
}
-static __init int cpu_has_kvm_support(void)
-{
- return cpu_has_vmx();
-}
-
-static __init int vmx_disabled_by_bios(void)
-{
- return !this_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) ||
- !this_cpu_has(X86_FEATURE_VMX);
-}
-
static int kvm_cpu_vmxon(u64 vmxon_pointer)
{
u64 msr;
@@ -7479,16 +7468,29 @@ static int vmx_vm_init(struct kvm *kvm)
return 0;
}
+static bool __init kvm_is_vmx_supported(void)
+{
+ if (!cpu_has_vmx()) {
+ pr_err("CPU doesn't support VMX\n");
+ return false;
+ }
+
+ if (!this_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) ||
+ !this_cpu_has(X86_FEATURE_VMX)) {
+ pr_err("VMX not enabled (by BIOS) in MSR_IA32_FEAT_CTL\n");
+ return false;
+ }
+
+ return true;
+}
+
static int __init vmx_check_processor_compat(void)
{
struct vmcs_config vmcs_conf;
struct vmx_capability vmx_cap;
- if (!this_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) ||
- !this_cpu_has(X86_FEATURE_VMX)) {
- pr_err("VMX is disabled on CPU %d\n", smp_processor_id());
+ if (!kvm_is_vmx_supported())
return -EIO;
- }
if (setup_vmcs_config(&vmcs_conf, &vmx_cap) < 0)
return -EIO;
@@ -8499,8 +8501,6 @@ static __init int hardware_setup(void)
}
static struct kvm_x86_init_ops vmx_init_ops __initdata = {
- .cpu_has_kvm_support = cpu_has_kvm_support,
- .disabled_by_bios = vmx_disabled_by_bios,
.check_processor_compatibility = vmx_check_processor_compat,
.hardware_setup = hardware_setup,
.handle_intel_pt_intr = NULL,
@@ -8543,6 +8543,9 @@ static int __init vmx_init(void)
{
int r, cpu;
+ if (!kvm_is_vmx_supported())
+ return -EOPNOTSUPP;
+
/*
* Note, hv_init_evmcs() touches only VMX knobs, i.e. there's nothing
* to unwind if a later step fails.
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3d5455e08191..5551f3552f08 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9315,17 +9315,6 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops)
return -EEXIST;
}
- if (!ops->cpu_has_kvm_support()) {
- pr_err_ratelimited("no hardware support for '%s'\n",
- ops->runtime_ops->name);
- return -EOPNOTSUPP;
- }
- if (ops->disabled_by_bios()) {
- pr_err_ratelimited("support for '%s' disabled by bios\n",
- ops->runtime_ops->name);
- return -EOPNOTSUPP;
- }
-
/*
* KVM explicitly assumes that the guest has an FPU and
* FXSAVE/FXRSTOR. For example, the KVM_GET_FPU explicitly casts the
--
2.38.1.584.g0f3c55d4c2-goog
next prev parent reply other threads:[~2022-11-30 23:51 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-30 23:08 [PATCH v2 00/50] KVM: Rework kvm_init() and hardware enabling Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 01/50] KVM: Register /dev/kvm as the _very_ last thing during initialization Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 02/50] KVM: Initialize IRQ FD after arch hardware setup Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 03/50] KVM: Allocate cpus_hardware_enabled " Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 04/50] KVM: Teardown VFIO ops earlier in kvm_exit() Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 05/50] KVM: s390: Unwind kvm_arch_init() piece-by-piece() if a step fails Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 06/50] KVM: s390: Move hardware setup/unsetup to init/exit Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 07/50] KVM: x86: Do timer initialization after XCR0 configuration Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 08/50] KVM: x86: Move hardware setup/unsetup to init/exit Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 09/50] KVM: Drop arch hardware (un)setup hooks Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 10/50] KVM: VMX: Reset eVMCS controls in VP assist page during hardware disabling Sean Christopherson
2022-12-01 15:42 ` Vitaly Kuznetsov
2022-11-30 23:08 ` [PATCH v2 11/50] KVM: VMX: Don't bother disabling eVMCS static key on module exit Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 12/50] KVM: VMX: Move Hyper-V eVMCS initialization to helper Sean Christopherson
2022-12-01 15:22 ` Vitaly Kuznetsov
2022-11-30 23:08 ` [PATCH v2 13/50] KVM: x86: Move guts of kvm_arch_init() to standalone helper Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 14/50] KVM: VMX: Do _all_ initialization before exposing /dev/kvm to userspace Sean Christopherson
2022-11-30 23:08 ` [PATCH v2 15/50] KVM: x86: Serialize vendor module initialization (hardware setup) Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 16/50] KVM: arm64: Simplify the CPUHP logic Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 17/50] KVM: arm64: Free hypervisor allocations if vector slot init fails Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 18/50] KVM: arm64: Unregister perf callbacks if hypervisor finalization fails Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 19/50] KVM: arm64: Do arm/arch initialization without bouncing through kvm_init() Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 20/50] KVM: arm64: Mark kvm_arm_init() and its unique descendants as __init Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 21/50] KVM: MIPS: Hardcode callbacks to hardware virtualization extensions Sean Christopherson
2022-12-01 22:00 ` Philippe Mathieu-Daudé
2022-12-01 22:49 ` Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 22/50] KVM: MIPS: Setup VZ emulation? directly from kvm_mips_init() Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 23/50] KVM: MIPS: Register die notifier prior to kvm_init() Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 24/50] KVM: RISC-V: Do arch init directly in riscv_kvm_init() Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 25/50] KVM: RISC-V: Tag init functions and data with __init, __ro_after_init Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 26/50] KVM: PPC: Move processor compatibility check to module init Sean Christopherson
2022-12-01 5:21 ` Michael Ellerman
2022-12-01 16:38 ` Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 27/50] KVM: s390: Do s390 specific init without bouncing through kvm_init() Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 28/50] KVM: s390: Mark __kvm_s390_init() and its descendants as __init Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 29/50] KVM: Drop kvm_arch_{init,exit}() hooks Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 30/50] KVM: VMX: Make VMCS configuration/capabilities structs read-only after init Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 31/50] KVM: x86: Do CPU compatibility checks in x86 code Sean Christopherson
2022-12-02 12:16 ` Huang, Kai
2022-12-05 20:52 ` Isaku Yamahata
2022-12-05 21:12 ` Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 32/50] KVM: Drop kvm_arch_check_processor_compat() hook Sean Christopherson
2022-12-02 12:18 ` Huang, Kai
2022-11-30 23:09 ` [PATCH v2 33/50] KVM: x86: Use KBUILD_MODNAME to specify vendor module name Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 34/50] KVM: x86: Unify pr_fmt to use module name for all KVM modules Sean Christopherson
2022-12-01 10:43 ` Paul Durrant
2022-11-30 23:09 ` [PATCH v2 35/50] KVM: VMX: Use current CPU's info to perform "disabled by BIOS?" checks Sean Christopherson
2022-12-02 12:18 ` Huang, Kai
2022-11-30 23:09 ` Sean Christopherson [this message]
2022-11-30 23:09 ` [PATCH v2 37/50] KVM: VMX: Shuffle support checks and hardware enabling code around Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 38/50] KVM: SVM: Check for SVM support in CPU compatibility checks Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 39/50] KVM: x86: Move CPU compat checks hook to kvm_x86_ops (from kvm_x86_init_ops) Sean Christopherson
2022-12-02 13:01 ` Huang, Kai
2022-12-05 21:04 ` Isaku Yamahata
2022-11-30 23:09 ` [PATCH v2 40/50] KVM: x86: Do compatibility checks when onlining CPU Sean Christopherson
2022-12-02 13:03 ` Huang, Kai
2022-12-02 13:36 ` Huang, Kai
2022-12-02 16:04 ` Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 41/50] KVM: Rename and move CPUHP_AP_KVM_STARTING to ONLINE section Sean Christopherson
2022-12-02 13:06 ` Huang, Kai
2022-12-02 16:08 ` Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 42/50] KVM: Disable CPU hotplug during hardware enabling/disabling Sean Christopherson
2022-12-02 12:59 ` Huang, Kai
2022-12-02 16:31 ` Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 43/50] KVM: Ensure CPU is stable during low level hardware enable/disable Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 44/50] KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 45/50] KVM: Remove on_each_cpu(hardware_disable_nolock) in kvm_exit() Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 46/50] KVM: Use a per-CPU variable to track which CPUs have enabled virtualization Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 47/50] KVM: Make hardware_enable_failed a local variable in the "enable all" path Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 48/50] KVM: Register syscore (suspend/resume) ops early in kvm_init() Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 49/50] KVM: Opt out of generic hardware enabling on s390 and PPC Sean Christopherson
2022-11-30 23:09 ` [PATCH v2 50/50] KVM: Clean up error labels in kvm_init() Sean Christopherson
2022-12-02 8:02 ` [PATCH v2 00/50] KVM: Rework kvm_init() and hardware enabling Chao Gao
2022-12-27 13:02 ` Paolo Bonzini
2022-12-28 11:22 ` Marc Zyngier
2022-12-28 11:58 ` Paolo Bonzini
2022-12-29 20:52 ` Paolo Bonzini
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