Commit 07036264 authored by Fuad Tabba's avatar Fuad Tabba Committed by Marc Zyngier
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KVM: arm64: Clarify comments to distinguish pKVM mode from protected VMs 



The hypervisor code for protected KVM contains comments that are
imprecise and at times flat-out wrong. They often refer to a "protected
VM" in contexts where the code or data structure applies to _any_ VM
managed by the hypervisor when pKVM is enabled.

For instance, the 'vm_table' holds handles for all VMs known to the
hypervisor, not exclusively for those that are configured as protected.
This inaccurate terminology can make the code scope harder to understand
for future (and current) developers.

Clarify the comments throughout the pKVM hypervisor code to make a clear
distinction between the pKVM feature itself (i.e., "protected mode") and
the VMs that are specifically configured to be protected. This involves
replacing ambiguous uses of "protected VM" with more accurate phrasing.

No functional change intended.

Signed-off-by: default avatarFuad Tabba <tabba@google.com>
Tested-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 604a5032

arch/arm64/kvm/hyp/include/nvhe/pkvm.h

+1 −1
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ struct pkvm_hyp_vcpu { 
};



/*

 * Holds the relevant data for running a protected vm.

 * Holds the relevant data for running a vm in protected mode.

 */

struct pkvm_hyp_vm {

	struct kvm kvm;

arch/arm64/kvm/hyp/nvhe/pkvm.c

+11 −14
Original line number Diff line number Diff line
@@ -23,8 +23,8 @@ unsigned int kvm_arm_vmid_bits; 
unsigned int kvm_host_sve_max_vl;



/*

 * The currently loaded hyp vCPU for each physical CPU. Used only when

 * protected KVM is enabled, but for both protected and non-protected VMs.

 * The currently loaded hyp vCPU for each physical CPU. Used in protected mode

 * for both protected and non-protected VMs.

 */

static DEFINE_PER_CPU(struct pkvm_hyp_vcpu *, loaded_hyp_vcpu);
@@ -135,7 +135,7 @@ static int pkvm_check_pvm_cpu_features(struct kvm_vcpu *vcpu) 
{

	struct kvm *kvm = vcpu->kvm;



	/* Protected KVM does not support AArch32 guests. */

	/* No AArch32 support for protected guests. */

	if (kvm_has_feat(kvm, ID_AA64PFR0_EL1, EL0, AARCH32) ||

	    kvm_has_feat(kvm, ID_AA64PFR0_EL1, EL1, AARCH32))

		return -EINVAL;
@@ -210,8 +210,8 @@ static pkvm_handle_t idx_to_vm_handle(unsigned int idx) 
DEFINE_HYP_SPINLOCK(vm_table_lock);



/*

 * The table of VM entries for protected VMs in hyp.

 * Allocated at hyp initialization and setup.

 * A table that tracks all VMs in protected mode.

 * Allocated during hyp initialization and setup.

 */

static struct pkvm_hyp_vm **vm_table;
@@ -495,7 +495,7 @@ static int find_free_vm_table_entry(struct kvm *host_kvm) 
/*

 * Allocate a VM table entry and insert a pointer to the new vm.

 *

 * Return a unique handle to the protected VM on success,

 * Return a unique handle to the VM on success,

 * negative error code on failure.

 */

static pkvm_handle_t insert_vm_table_entry(struct kvm *host_kvm,
@@ -594,10 +594,8 @@ static void unmap_donated_memory_noclear(void *va, size_t size) 
}



/*

 * Initialize the hypervisor copy of the protected VM state using the

 * memory donated by the host.

 *

 * Unmaps the donated memory from the host at stage 2.

 * Initialize the hypervisor copy of the VM state using host-donated memory.

 * Unmap the donated memory from the host at stage 2.

 *

 * host_kvm: A pointer to the host's struct kvm.

 * vm_hva: The host va of the area being donated for the VM state.
@@ -606,7 +604,7 @@ static void unmap_donated_memory_noclear(void *va, size_t size) 
 *	    the VM. Must be page aligned. Its size is implied by the VM's

 *	    VTCR.

 *

 * Return a unique handle to the protected VM on success,

 * Return a unique handle to the VM on success,

 * negative error code on failure.

 */

int __pkvm_init_vm(struct kvm *host_kvm, unsigned long vm_hva,
@@ -668,10 +666,9 @@ int __pkvm_init_vm(struct kvm *host_kvm, unsigned long vm_hva, 
}



/*

 * Initialize the hypervisor copy of the protected vCPU state using the

 * memory donated by the host.

 * Initialize the hypervisor copy of the vCPU state using host-donated memory.

 *

 * handle: The handle for the protected vm.

 * handle: The hypervisor handle for the vm.

 * host_vcpu: A pointer to the corresponding host vcpu.

 * vcpu_hva: The host va of the area being donated for the vcpu state.

 *	     Must be page aligned. The size of the area must be equal to