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| author |   Sean Christopherson <seanjc@google.com> | 2023-02-07 00:21:56 +0000 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2023-03-14 10:20:07 -0400 |
| commit | c281794eaa5c635c0edf39c6a9a3b0171000e92f (patch) | |
| tree | 5c441f2f6a695a8c3215d15c72d6899c2c2df09e /arch | |
| parent | KVM: SVM: Modify AVIC GATag to support max number of 512 vCPUs (diff) | |
| download | wireguard-linux-c281794eaa5c635c0edf39c6a9a3b0171000e92f.tar.xz wireguard-linux-c281794eaa5c635c0edf39c6a9a3b0171000e92f.zip | |
KVM: SVM: WARN if GATag generation drops VM or vCPU ID information
WARN if generating a GATag given a VM ID and vCPU ID doesn't yield the
same IDs when pulling the IDs back out of the tag. Don't bother adding
error handling to callers, this is very much a paranoid sanity check as
KVM fully controls the VM ID and is supposed to reject too-big vCPU IDs.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <20230207002156.521736-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/svm/avic.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 326341a22153..cfc8ab773025 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -43,12 +43,21 @@ #define AVIC_VM_ID_SHIFT HWEIGHT32(AVIC_PHYSICAL_MAX_INDEX_MASK) #define AVIC_VM_ID_MASK (GENMASK(31, AVIC_VM_ID_SHIFT) >> AVIC_VM_ID_SHIFT) -#define AVIC_GATAG(x, y) (((x & AVIC_VM_ID_MASK) << AVIC_VM_ID_SHIFT) | \ - (y & AVIC_VCPU_ID_MASK)) #define AVIC_GATAG_TO_VMID(x) ((x >> AVIC_VM_ID_SHIFT) & AVIC_VM_ID_MASK) #define AVIC_GATAG_TO_VCPUID(x) (x & AVIC_VCPU_ID_MASK) -static_assert(AVIC_GATAG(AVIC_VM_ID_MASK, AVIC_VCPU_ID_MASK) == -1u); +#define __AVIC_GATAG(vm_id, vcpu_id) ((((vm_id) & AVIC_VM_ID_MASK) << AVIC_VM_ID_SHIFT) | \ + ((vcpu_id) & AVIC_VCPU_ID_MASK)) +#define AVIC_GATAG(vm_id, vcpu_id) \ +({ \ + u32 ga_tag = __AVIC_GATAG(vm_id, vcpu_id); \ + \ + WARN_ON_ONCE(AVIC_GATAG_TO_VCPUID(ga_tag) != (vcpu_id)); \ + WARN_ON_ONCE(AVIC_GATAG_TO_VMID(ga_tag) != (vm_id)); \ + ga_tag; \ +}) + +static_assert(__AVIC_GATAG(AVIC_VM_ID_MASK, AVIC_VCPU_ID_MASK) == -1u); static bool force_avic; module_param_unsafe(force_avic, bool, 0444); |