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authorLinus Torvalds <torvalds@linux-foundation.org>2024-01-17 13:03:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2024-01-17 13:03:37 -0800
commit09d1c6a80f2cf94c6e70be919203473d4ab8e26c (patch)
tree144604e6cf9f513c45c4d035548ac1760e7dac11 /arch/x86/kvm/cpuid.c
parent1b1934dbbdcf9aa2d507932ff488cec47999cf3f (diff)
parent1c6d984f523f67ecfad1083bb04c55d91977bb15 (diff)
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini: "Generic: - Use memdup_array_user() to harden against overflow. - Unconditionally advertise KVM_CAP_DEVICE_CTRL for all architectures. - Clean up Kconfigs that all KVM architectures were selecting - New functionality around "guest_memfd", a new userspace API that creates an anonymous file and returns a file descriptor that refers to it. guest_memfd files are bound to their owning virtual machine, cannot be mapped, read, or written by userspace, and cannot be resized. guest_memfd files do however support PUNCH_HOLE, which can be used to switch a memory area between guest_memfd and regular anonymous memory. - New ioctl KVM_SET_MEMORY_ATTRIBUTES allowing userspace to specify per-page attributes for a given page of guest memory; right now the only attribute is whether the guest expects to access memory via guest_memfd or not, which in Confidential SVMs backed by SEV-SNP, TDX or ARM64 pKVM is checked by firmware or hypervisor that guarantees confidentiality (AMD PSP, Intel TDX module, or EL2 in the case of pKVM). x86: - Support for "software-protected VMs" that can use the new guest_memfd and page attributes infrastructure. This is mostly useful for testing, since there is no pKVM-like infrastructure to provide a meaningfully reduced TCB. - Fix a relatively benign off-by-one error when splitting huge pages during CLEAR_DIRTY_LOG. - Fix a bug where KVM could incorrectly test-and-clear dirty bits in non-leaf TDP MMU SPTEs if a racing thread replaces a huge SPTE with a non-huge SPTE. - Use more generic lockdep assertions in paths that don't actually care about whether the caller is a reader or a writer. - let Xen guests opt out of having PV clock reported as "based on a stable TSC", because some of them don't expect the "TSC stable" bit (added to the pvclock ABI by KVM, but never set by Xen) to be set. - Revert a bogus, made-up nested SVM consistency check for TLB_CONTROL. - Advertise flush-by-ASID support for nSVM unconditionally, as KVM always flushes on nested transitions, i.e. always satisfies flush requests. This allows running bleeding edge versions of VMware Workstation on top of KVM. - Sanity check that the CPU supports flush-by-ASID when enabling SEV support. - On AMD machines with vNMI, always rely on hardware instead of intercepting IRET in some cases to detect unmasking of NMIs - Support for virtualizing Linear Address Masking (LAM) - Fix a variety of vPMU bugs where KVM fail to stop/reset counters and other state prior to refreshing the vPMU model. - Fix a double-overflow PMU bug by tracking emulated counter events using a dedicated field instead of snapshotting the "previous" counter. If the hardware PMC count triggers overflow that is recognized in the same VM-Exit that KVM manually bumps an event count, KVM would pend PMIs for both the hardware-triggered overflow and for KVM-triggered overflow. - Turn off KVM_WERROR by default for all configs so that it's not inadvertantly enabled by non-KVM developers, which can be problematic for subsystems that require no regressions for W=1 builds. - Advertise all of the host-supported CPUID bits that enumerate IA32_SPEC_CTRL "features". - Don't force a masterclock update when a vCPU synchronizes to the current TSC generation, as updating the masterclock can cause kvmclock's time to "jump" unexpectedly, e.g. when userspace hotplugs a pre-created vCPU. - Use RIP-relative address to read kvm_rebooting in the VM-Enter fault paths, partly as a super minor optimization, but mostly to make KVM play nice with position independent executable builds. - Guard KVM-on-HyperV's range-based TLB flush hooks with an #ifdef on CONFIG_HYPERV as a minor optimization, and to self-document the code. - Add CONFIG_KVM_HYPERV to allow disabling KVM support for HyperV "emulation" at build time. ARM64: - LPA2 support, adding 52bit IPA/PA capability for 4kB and 16kB base granule sizes. Branch shared with the arm64 tree. - Large Fine-Grained Trap rework, bringing some sanity to the feature, although there is more to come. This comes with a prefix branch shared with the arm64 tree. - Some additional Nested Virtualization groundwork, mostly introducing the NV2 VNCR support and retargetting the NV support to that version of the architecture. - A small set of vgic fixes and associated cleanups. Loongarch: - Optimization for memslot hugepage checking - Cleanup and fix some HW/SW timer issues - Add LSX/LASX (128bit/256bit SIMD) support RISC-V: - KVM_GET_REG_LIST improvement for vector registers - Generate ISA extension reg_list using macros in get-reg-list selftest - Support for reporting steal time along with selftest s390: - Bugfixes Selftests: - Fix an annoying goof where the NX hugepage test prints out garbage instead of the magic token needed to run the test. - Fix build errors when a header is delete/moved due to a missing flag in the Makefile. - Detect if KVM bugged/killed a selftest's VM and print out a helpful message instead of complaining that a random ioctl() failed. - Annotate the guest printf/assert helpers with __printf(), and fix the various bugs that were lurking due to lack of said annotation" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (185 commits) x86/kvm: Do not try to disable kvmclock if it was not enabled KVM: x86: add missing "depends on KVM" KVM: fix direction of dependency on MMU notifiers KVM: introduce CONFIG_KVM_COMMON KVM: arm64: Add missing memory barriers when switching to pKVM's hyp pgd KVM: arm64: vgic-its: Avoid potential UAF in LPI translation cache RISC-V: KVM: selftests: Add get-reg-list test for STA registers RISC-V: KVM: selftests: Add steal_time test support RISC-V: KVM: selftests: Add guest_sbi_probe_extension RISC-V: KVM: selftests: Move sbi_ecall to processor.c RISC-V: KVM: Implement SBI STA extension RISC-V: KVM: Add support for SBI STA registers RISC-V: KVM: Add support for SBI extension registers RISC-V: KVM: Add SBI STA info to vcpu_arch RISC-V: KVM: Add steal-update vcpu request RISC-V: KVM: Add SBI STA extension skeleton RISC-V: paravirt: Implement steal-time support RISC-V: Add SBI STA extension definitions RISC-V: paravirt: Add skeleton for pv-time support RISC-V: KVM: Fix indentation in kvm_riscv_vcpu_set_reg_csr() ...
Diffstat (limited to 'arch/x86/kvm/cpuid.c')
-rw-r--r--arch/x86/kvm/cpuid.c33
1 files changed, 27 insertions, 6 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 42d3f47f4c07..adba49afb5fe 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -314,11 +314,15 @@ EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime);
static bool kvm_cpuid_has_hyperv(struct kvm_cpuid_entry2 *entries, int nent)
{
+#ifdef CONFIG_KVM_HYPERV
struct kvm_cpuid_entry2 *entry;
entry = cpuid_entry2_find(entries, nent, HYPERV_CPUID_INTERFACE,
KVM_CPUID_INDEX_NOT_SIGNIFICANT);
return entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX;
+#else
+ return false;
+#endif
}
static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
@@ -433,11 +437,13 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
return 0;
}
+#ifdef CONFIG_KVM_HYPERV
if (kvm_cpuid_has_hyperv(e2, nent)) {
r = kvm_hv_vcpu_init(vcpu);
if (r)
return r;
}
+#endif
r = kvm_check_cpuid(vcpu, e2, nent);
if (r)
@@ -469,7 +475,7 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
return -E2BIG;
if (cpuid->nent) {
- e = vmemdup_user(entries, array_size(sizeof(*e), cpuid->nent));
+ e = vmemdup_array_user(entries, cpuid->nent, sizeof(*e));
if (IS_ERR(e))
return PTR_ERR(e);
@@ -513,7 +519,7 @@ int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
return -E2BIG;
if (cpuid->nent) {
- e2 = vmemdup_user(entries, array_size(sizeof(*e2), cpuid->nent));
+ e2 = vmemdup_array_user(entries, cpuid->nent, sizeof(*e2));
if (IS_ERR(e2))
return PTR_ERR(e2);
}
@@ -671,7 +677,7 @@ void kvm_set_cpu_caps(void)
kvm_cpu_cap_mask(CPUID_7_1_EAX,
F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) |
F(FZRM) | F(FSRS) | F(FSRC) |
- F(AMX_FP16) | F(AVX_IFMA)
+ F(AMX_FP16) | F(AVX_IFMA) | F(LAM)
);
kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX,
@@ -679,6 +685,11 @@ void kvm_set_cpu_caps(void)
F(AMX_COMPLEX)
);
+ kvm_cpu_cap_init_kvm_defined(CPUID_7_2_EDX,
+ F(INTEL_PSFD) | F(IPRED_CTRL) | F(RRSBA_CTRL) | F(DDPD_U) |
+ F(BHI_CTRL) | F(MCDT_NO)
+ );
+
kvm_cpu_cap_mask(CPUID_D_1_EAX,
F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | F(XSAVES) | f_xfd
);
@@ -960,13 +971,13 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
break;
/* function 7 has additional index. */
case 7:
- entry->eax = min(entry->eax, 1u);
+ max_idx = entry->eax = min(entry->eax, 2u);
cpuid_entry_override(entry, CPUID_7_0_EBX);
cpuid_entry_override(entry, CPUID_7_ECX);
cpuid_entry_override(entry, CPUID_7_EDX);
- /* KVM only supports 0x7.0 and 0x7.1, capped above via min(). */
- if (entry->eax == 1) {
+ /* KVM only supports up to 0x7.2, capped above via min(). */
+ if (max_idx >= 1) {
entry = do_host_cpuid(array, function, 1);
if (!entry)
goto out;
@@ -976,6 +987,16 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->ebx = 0;
entry->ecx = 0;
}
+ if (max_idx >= 2) {
+ entry = do_host_cpuid(array, function, 2);
+ if (!entry)
+ goto out;
+
+ cpuid_entry_override(entry, CPUID_7_2_EDX);
+ entry->ecx = 0;
+ entry->ebx = 0;
+ entry->eax = 0;
+ }
break;
case 0xa: { /* Architectural Performance Monitoring */
union cpuid10_eax eax;