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KVM: arm64: Reject the stage-2 flush hypercalls under pKVM

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The stage-2 TLB and context flush hypercalls remain callable once pKVM
has finalised, and five of the six dereference a host-supplied
struct kvm_s2_mmu pointer. Under pKVM none has a valid caller: the host
walks no guest stage-2, its TLB flushes go through the handle-based
__pkvm_tlb_flush_vmid, and kvm_arch_vcpu_load() skips both the VMID
update and the CPU context flush.

Move them into the band the dispatcher rejects once pKVM has finalised.

[maz: Dropped cosmetic hyp-main.c changes]

Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260914130152.F0D5F1F000FF@smtp.kernel.org/
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20261012161524.4016464-3-fuad.tabba@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Fuad Tabba 2026-10-17 17:13:50 +01:00 committed by Marc Zyngier
parent ecb6b43cd2
commit 121d74bee8
2 changed files with 8 additions and 7 deletions
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12
arch/arm64/include/asm/kvm_asm.h
View File

@ -64,6 +64,12 @@ enum __kvm_host_smccc_func {
__KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config,
__KVM_HOST_SMCCC_FUNC___vgic_v5_save_apr,
__KVM_HOST_SMCCC_FUNC___vgic_v5_restore_vmcr_apr,
__KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa,
__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa_nsh,
__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid,
__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_range,
__KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
MARKER(__KVM_HOST_SMCCC_FUNC_MIN_PKVM),
@ -72,12 +78,6 @@ enum __kvm_host_smccc_func {
/* Hypercalls that are always available and common to [nh]VHE/pKVM. */
__KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
__KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
__KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa,
__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa_nsh,
__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid,
__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_range,
__KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
__KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
__KVM_HOST_SMCCC_FUNC___tracing_load,
__KVM_HOST_SMCCC_FUNC___tracing_unload,

3
arch/arm64/kvm/hyp/nvhe/hyp-main.c
View File

@ -969,7 +969,8 @@ static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
/*
* If pKVM has been initialised then reject any calls to the
* early "privileged" hypercalls. Note that we cannot reject
* early "privileged" hypercalls, and to the ones the host has no
* use for in protected mode. Note that we cannot reject
* calls to __pkvm_prot_finalize for two reasons: (1) The static
* key used to determine initialisation must be toggled prior to
* finalisation and (2) finalisation is performed on a per-CPU