diff options
| author | Santosh Shukla <santosh.shukla@amd.com> | 2023-02-27 11:40:15 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-03-23 03:43:22 +0300 |
| commit | fa4c027a7956f5e07697bfcb580d25eeb8471257 (patch) | |
| tree | 302abc2013362ae3cb0eb239554d21161311293e /arch/x86/include/asm/kvm_host.h | |
| parent | bdedff263132c862924f5cad96f0e82eeeb4e2e6 (diff) | |
| download | linux-fa4c027a7956f5e07697bfcb580d25eeb8471257.tar.xz | |
KVM: x86: Add support for SVM's Virtual NMI
Add support for SVM's Virtual NMIs implementation, which adds proper
tracking of virtual NMI blocking, and an intr_ctrl flag that software can
set to mark a virtual NMI as pending. Pending virtual NMIs are serviced
by hardware if/when virtual NMIs become unblocked, i.e. act more or less
like real NMIs.
Introduce two new kvm_x86_ops callbacks so to support SVM's vNMI, as KVM
needs to treat a pending vNMI as partially injected. Specifically, if
two NMIs (for L1) arrive concurrently in KVM's software model, KVM's ABI
is to inject one and pend the other. Without vNMI, KVM manually tracks
the pending NMI and uses NMI windows to detect when the NMI should be
injected.
With vNMI, the pending NMI is simply stuffed into the VMCB and handed
off to hardware. This means that KVM needs to be able to set a vNMI
pending on-demand, and also query if a vNMI is pending, e.g. to honor the
"at most one NMI pending" rule and to preserve all NMIs across save and
restore.
Warn if KVM attempts to open an NMI window when vNMI is fully enabled,
as the above logic should prevent KVM from ever getting to
kvm_check_and_inject_events() with two NMIs pending _in software_, and
the "at most one NMI pending" logic should prevent having an NMI pending
in hardware and an NMI pending in software if NMIs are also blocked, i.e.
if KVM can't immediately inject the second NMI.
Signed-off-by: Santosh Shukla <Santosh.Shukla@amd.com>
Co-developed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20230227084016.3368-11-santosh.shukla@amd.com
[sean: rewrite shortlog and changelog, massage code comments]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/include/asm/kvm_host.h')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a45de1118a42..3edb8b3e3ef5 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -876,7 +876,8 @@ struct kvm_vcpu_arch { u64 tsc_scaling_ratio; /* current scaling ratio */ atomic_t nmi_queued; /* unprocessed asynchronous NMIs */ - unsigned nmi_pending; /* NMI queued after currently running handler */ + /* Number of NMIs pending injection, not including hardware vNMIs. */ + unsigned int nmi_pending; bool nmi_injected; /* Trying to inject an NMI this entry */ bool smi_pending; /* SMI queued after currently running handler */ u8 handling_intr_from_guest; @@ -1621,6 +1622,13 @@ struct kvm_x86_ops { int (*nmi_allowed)(struct kvm_vcpu *vcpu, bool for_injection); bool (*get_nmi_mask)(struct kvm_vcpu *vcpu); void (*set_nmi_mask)(struct kvm_vcpu *vcpu, bool masked); + /* Whether or not a virtual NMI is pending in hardware. */ + bool (*is_vnmi_pending)(struct kvm_vcpu *vcpu); + /* + * Attempt to pend a virtual NMI in harware. Returns %true on success + * to allow using static_call_ret0 as the fallback. + */ + bool (*set_vnmi_pending)(struct kvm_vcpu *vcpu); void (*enable_nmi_window)(struct kvm_vcpu *vcpu); void (*enable_irq_window)(struct kvm_vcpu *vcpu); void (*update_cr8_intercept)(struct kvm_vcpu *vcpu, int tpr, int irr); @@ -2005,6 +2013,7 @@ int kvm_pic_set_irq(struct kvm_pic *pic, int irq, int irq_source_id, int level); void kvm_pic_clear_all(struct kvm_pic *pic, int irq_source_id); void kvm_inject_nmi(struct kvm_vcpu *vcpu); +int kvm_get_nr_pending_nmis(struct kvm_vcpu *vcpu); void kvm_update_dr7(struct kvm_vcpu *vcpu); |