diff options
| author | Marc Zyngier <maz@kernel.org> | 2025-05-14 11:34:53 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2025-05-19 08:01:19 +0100 |
| commit | 2a359e072596fcb2e9e85017a865e3618a2fe5b5 (patch) | |
| tree | 3c845775cef5611729d4d1c7484870c4fa69b185 /arch/arm64/include | |
| parent | 069a05e53549685d2b5e54ceb51db1fd04aa50d7 (diff) | |
KVM: arm64: nv: Handle mapping of VNCR_EL2 at EL2
Now that we can handle faults triggered through VNCR_EL2, we need
to map the corresponding page at EL2. But where, you'll ask?
Since each CPU in the system can run a vcpu, we need a per-CPU
mapping. For that, we carve a NR_CPUS range in the fixmap, giving
us a per-CPU va at which to map the guest's VNCR's page.
The mapping occurs both on vcpu load and on the back of a fault,
both generating a request that will take care of the mapping.
That mapping will also get dropped on vcpu put.
Yes, this is a bit heavy handed, but it is simple. Eventually,
we may want to have a per-VM, per-CPU mapping, which would avoid
all the TLBI overhead.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250514103501.2225951-11-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/fixmap.h | 6 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_nested.h | 7 |
3 files changed, 14 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h index 87e307804b99..635a43c4ec85 100644 --- a/arch/arm64/include/asm/fixmap.h +++ b/arch/arm64/include/asm/fixmap.h @@ -48,6 +48,12 @@ enum fixed_addresses { FIX_EARLYCON_MEM_BASE, FIX_TEXT_POKE0, +#ifdef CONFIG_KVM + /* One slot per CPU, mapping the guest's VNCR page at EL2. */ + FIX_VNCR_END, + FIX_VNCR = FIX_VNCR_END + NR_CPUS, +#endif + #ifdef CONFIG_ACPI_APEI_GHES /* Used for GHES mapping from assorted contexts */ FIX_APEI_GHES_IRQ, diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 8fb1c8d5fd14..d87fed0b4833 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -658,6 +658,7 @@ struct kvm_host_data { #define KVM_HOST_DATA_FLAG_TRBE_ENABLED 4 #define KVM_HOST_DATA_FLAG_EL1_TRACING_CONFIGURED 5 #define KVM_HOST_DATA_FLAG_VCPU_IN_HYP_CONTEXT 6 +#define KVM_HOST_DATA_FLAG_L1_VNCR_MAPPED 7 unsigned long flags; struct kvm_cpu_context host_ctxt; diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index be4be8ec49d9..ea50cad1a6a2 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -337,4 +337,11 @@ int __kvm_translate_va(struct kvm_vcpu *vcpu, struct s1_walk_info *wi, int kvm_vcpu_allocate_vncr_tlb(struct kvm_vcpu *vcpu); int kvm_handle_vncr_abort(struct kvm_vcpu *vcpu); +#define vncr_fixmap(c) \ + ({ \ + u32 __c = (c); \ + BUG_ON(__c >= NR_CPUS); \ + (FIX_VNCR - __c); \ + }) + #endif /* __ARM64_KVM_NESTED_H */ |