diff options
| author | Lorenzo Stoakes (ARM) <ljs@kernel.org> | 2026-09-23 16:15:44 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2026-09-24 23:28:13 +0100 |
| commit | caa63620f9e37a5eec4d0af13534ebd6c0d33f97 (patch) | |
| tree | 3444bb44d6aaaad9ba9033a2f62c2562840ae981 /include/linux | |
| parent | c2778d14cd2ff757224715221a2ddff89fc6f127 (diff) | |
KVM: Allow architectures to disallow pre-fault
All existing architectures which implement KVM pre-fault (x86, s390) have
mechanisms for disallowing pre-faulting.
Currently these are open coded as part of kvm_arch_vcpu_pre_fault_memory().
Formalise this by moving them into a new kvm_arch_pre_fault_allowed() hook,
which every architecture selecting CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY must
implement, returning an error code if the operation is disallowed or 0
otherwise.
The hook is called early in the generic code, allowing architectures to
disallow the operation prior to vCPU load.
This is important, as kvm_vcpu_pre_fault_memory() is the only place where
generic code can call vcpu_load() on a vCPU that has not yet been
initialised.
This lays the foundation for a future change which implements pre-faulting
for arm64 which needs to disallow the mechanism for uninitialised vCPUs.
Suggested-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260923-kvm-arm-prefault-v4-1-d4b0b4dfa8c3@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/kvm_host.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 03bfc92864b6..39a4d345aeca 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2643,6 +2643,7 @@ void kvm_arch_gmem_invalidate_range(struct kvm *kvm, struct kvm_gfn_range *range #endif #ifdef CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY +int kvm_arch_pre_fault_allowed(struct kvm_vcpu *vcpu); long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, struct kvm_pre_fault_memory *range); #endif |