| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <ee919bfcd4a57cde7debe7bd54d3cbd04d3ba15c.camel@redhat.com>
Date: Thu, 04 Jul 2024 21:51:47 -0400
From: Maxim Levitsky <mlevitsk@...hat.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini
<pbonzini@...hat.com>, Vitaly Kuznetsov <vkuznets@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, Hou Wenlong
<houwenlong.hwl@...group.com>, Kechen Lu <kechenl@...dia.com>, Oliver Upton
<oliver.upton@...ux.dev>, Binbin Wu <binbin.wu@...ux.intel.com>, Yang
Weijiang <weijiang.yang@...el.com>, Robert Hoo <robert.hoo.linux@...il.com>
Subject: Re: [PATCH v2 30/49] KVM: x86: Always operate on kvm_vcpu data in
cpuid_entry2_find()
On Fri, 2024-05-17 at 10:39 -0700, Sean Christopherson wrote:
> Now that KVM sets vcpu->arch.cpuid_{entries,nent} before processing the
> incoming CPUID entries during KVM_SET_CPUID{,2}, drop the @entries and
> @nent params from cpuid_entry2_find() and unconditionally operate on the
> vCPU state.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@...gle.com>
> ---
> arch/x86/kvm/cpuid.c | 62 +++++++++++++++-----------------------------
> 1 file changed, 21 insertions(+), 41 deletions(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 7290f91c422c..0526f25a7c80 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -124,8 +124,8 @@ u32 xstate_required_size(u64 xstate_bv, bool compacted)
> */
> #define KVM_CPUID_INDEX_NOT_SIGNIFICANT -1ull
>
> -static inline struct kvm_cpuid_entry2 *cpuid_entry2_find(
> - struct kvm_cpuid_entry2 *entries, int nent, u32 function, u64 index)
> +static struct kvm_cpuid_entry2 *cpuid_entry2_find(struct kvm_vcpu *vcpu,
> + u32 function, u64 index)
> {
> struct kvm_cpuid_entry2 *e;
> int i;
> @@ -142,8 +142,8 @@ static inline struct kvm_cpuid_entry2 *cpuid_entry2_find(
> */
> lockdep_assert_irqs_enabled();
>
> - for (i = 0; i < nent; i++) {
> - e = &entries[i];
> + for (i = 0; i < vcpu->arch.cpuid_nent; i++) {
> + e = &vcpu->arch.cpuid_entries[i];
>
> if (e->function != function)
> continue;
> @@ -177,8 +177,6 @@ static inline struct kvm_cpuid_entry2 *cpuid_entry2_find(
>
> static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
> {
> - struct kvm_cpuid_entry2 *entries = vcpu->arch.cpuid_entries;
> - int nent = vcpu->arch.cpuid_nent;
> struct kvm_cpuid_entry2 *best;
> u64 xfeatures;
>
> @@ -186,7 +184,7 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
> * The existing code assumes virtual address is 48-bit or 57-bit in the
> * canonical address checks; exit if it is ever changed.
> */
> - best = cpuid_entry2_find(entries, nent, 0x80000008,
> + best = cpuid_entry2_find(vcpu, 0x80000008,
> KVM_CPUID_INDEX_NOT_SIGNIFICANT);
> if (best) {
> int vaddr_bits = (best->eax & 0xff00) >> 8;
> @@ -199,7 +197,7 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
> * Exposing dynamic xfeatures to the guest requires additional
> * enabling in the FPU, e.g. to expand the guest XSAVE state size.
> */
> - best = cpuid_entry2_find(entries, nent, 0xd, 0);
> + best = cpuid_entry2_find(vcpu, 0xd, 0);
> if (!best)
> return 0;
>
> @@ -234,15 +232,15 @@ static int kvm_cpuid_check_equal(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2
> return 0;
> }
>
> -static struct kvm_hypervisor_cpuid __kvm_get_hypervisor_cpuid(struct kvm_cpuid_entry2 *entries,
> - int nent, const char *sig)
> +static struct kvm_hypervisor_cpuid kvm_get_hypervisor_cpuid(struct kvm_vcpu *vcpu,
> + const char *sig)
> {
> struct kvm_hypervisor_cpuid cpuid = {};
> struct kvm_cpuid_entry2 *entry;
> u32 base;
>
> for_each_possible_hypervisor_cpuid_base(base) {
> - entry = cpuid_entry2_find(entries, nent, base, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
> + entry = cpuid_entry2_find(vcpu, base, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
>
> if (entry) {
> u32 signature[3];
> @@ -262,13 +260,6 @@ static struct kvm_hypervisor_cpuid __kvm_get_hypervisor_cpuid(struct kvm_cpuid_e
> return cpuid;
> }
>
> -static struct kvm_hypervisor_cpuid kvm_get_hypervisor_cpuid(struct kvm_vcpu *vcpu,
> - const char *sig)
> -{
> - return __kvm_get_hypervisor_cpuid(vcpu->arch.cpuid_entries,
> - vcpu->arch.cpuid_nent, sig);
> -}
> -
> static u32 kvm_apply_cpuid_pv_features_quirk(struct kvm_vcpu *vcpu)
> {
> struct kvm_hypervisor_cpuid kvm_cpuid;
> @@ -292,23 +283,22 @@ static u32 kvm_apply_cpuid_pv_features_quirk(struct kvm_vcpu *vcpu)
> * Calculate guest's supported XCR0 taking into account guest CPUID data and
> * KVM's supported XCR0 (comprised of host's XCR0 and KVM_SUPPORTED_XCR0).
> */
> -static u64 cpuid_get_supported_xcr0(struct kvm_cpuid_entry2 *entries, int nent)
> +static u64 cpuid_get_supported_xcr0(struct kvm_vcpu *vcpu)
> {
> struct kvm_cpuid_entry2 *best;
>
> - best = cpuid_entry2_find(entries, nent, 0xd, 0);
> + best = cpuid_entry2_find(vcpu, 0xd, 0);
> if (!best)
> return 0;
>
> return (best->eax | ((u64)best->edx << 32)) & kvm_caps.supported_xcr0;
> }
>
> -static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *entries,
> - int nent)
> +void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
> {
> struct kvm_cpuid_entry2 *best;
>
> - best = cpuid_entry2_find(entries, nent, 1, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
> + best = cpuid_entry2_find(vcpu, 1, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
> if (best) {
> /* Update OSXSAVE bit */
> if (boot_cpu_has(X86_FEATURE_XSAVE))
> @@ -319,43 +309,36 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e
> vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE);
> }
>
> - best = cpuid_entry2_find(entries, nent, 7, 0);
> + best = cpuid_entry2_find(vcpu, 7, 0);
> if (best && boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7)
> cpuid_entry_change(best, X86_FEATURE_OSPKE,
> kvm_is_cr4_bit_set(vcpu, X86_CR4_PKE));
>
> - best = cpuid_entry2_find(entries, nent, 0xD, 0);
> + best = cpuid_entry2_find(vcpu, 0xD, 0);
> if (best)
> best->ebx = xstate_required_size(vcpu->arch.xcr0, false);
>
> - best = cpuid_entry2_find(entries, nent, 0xD, 1);
> + best = cpuid_entry2_find(vcpu, 0xD, 1);
> if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
> cpuid_entry_has(best, X86_FEATURE_XSAVEC)))
> best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
>
> if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) {
> - best = cpuid_entry2_find(entries, nent, 0x1, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
> + best = cpuid_entry2_find(vcpu, 0x1, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
> if (best)
> cpuid_entry_change(best, X86_FEATURE_MWAIT,
> vcpu->arch.ia32_misc_enable_msr &
> MSR_IA32_MISC_ENABLE_MWAIT);
> }
> }
> -
> -void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
> -{
> - __kvm_update_cpuid_runtime(vcpu, vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent);
> -}
> EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime);
>
> static bool kvm_cpuid_has_hyperv(struct kvm_vcpu *vcpu)
> {
> #ifdef CONFIG_KVM_HYPERV
> - struct kvm_cpuid_entry2 *entries = vcpu->arch.cpuid_entries;
> - int nent = vcpu->arch.cpuid_nent;
> struct kvm_cpuid_entry2 *entry;
>
> - entry = cpuid_entry2_find(entries, nent, HYPERV_CPUID_INTERFACE,
> + entry = cpuid_entry2_find(vcpu, HYPERV_CPUID_INTERFACE,
> KVM_CPUID_INDEX_NOT_SIGNIFICANT);
> return entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX;
> #else
> @@ -401,8 +384,7 @@ void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
> kvm_apic_set_version(vcpu);
> }
>
> - vcpu->arch.guest_supported_xcr0 =
> - cpuid_get_supported_xcr0(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent);
> + vcpu->arch.guest_supported_xcr0 = cpuid_get_supported_xcr0(vcpu);
>
> vcpu->arch.pv_cpuid.features = kvm_apply_cpuid_pv_features_quirk(vcpu);
>
> @@ -1532,16 +1514,14 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
> struct kvm_cpuid_entry2 *kvm_find_cpuid_entry_index(struct kvm_vcpu *vcpu,
> u32 function, u32 index)
> {
> - return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent,
> - function, index);
> + return cpuid_entry2_find(vcpu, function, index);
> }
> EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry_index);
>
> struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
> u32 function)
> {
> - return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent,
> - function, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
> + return cpuid_entry2_find(vcpu, function, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
> }
> EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
>
Reviewed-by: Maxim Levitsky <mlevitsk@...hat.com>
Best regards,
Maxim Levitsky
Powered by blists - more mailing lists