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Commit c40f2f8f authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Christoffer Dall
Browse files

arm/arm64: KVM: add 'writable' parameter to kvm_phys_addr_ioremap 



Add support for read-only MMIO passthrough mappings by adding a
'writable' parameter to kvm_phys_addr_ioremap. For the moment,
mappings will be read-write even if 'writable' is false, but once
the definition of PAGE_S2_DEVICE gets changed, those mappings will
be created read-only.

Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent 37b54408

arch/arm/include/asm/kvm_mmu.h

+1 −1
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ void free_hyp_pgds(void); 
int kvm_alloc_stage2_pgd(struct kvm *kvm);

void kvm_free_stage2_pgd(struct kvm *kvm);

int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,

			  phys_addr_t pa, unsigned long size);

			  phys_addr_t pa, unsigned long size, bool writable);



int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);

arch/arm/kvm/mmu.c

+4 −1
Original line number Diff line number Diff line
@@ -674,7 +674,7 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, 
 * @size:	The size of the mapping

 */

int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,

			  phys_addr_t pa, unsigned long size)

			  phys_addr_t pa, unsigned long size, bool writable)

{

	phys_addr_t addr, end;

	int ret = 0;
@@ -687,6 +687,9 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, 
	for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {

		pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);



		if (writable)

			kvm_set_s2pte_writable(&pte);



		ret = mmu_topup_memory_cache(&cache, 2, 2);

		if (ret)

			goto out;

arch/arm64/include/asm/kvm_mmu.h

+1 −1
Original line number Diff line number Diff line
@@ -77,7 +77,7 @@ void free_hyp_pgds(void); 
int kvm_alloc_stage2_pgd(struct kvm *kvm);

void kvm_free_stage2_pgd(struct kvm *kvm);

int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,

			  phys_addr_t pa, unsigned long size);

			  phys_addr_t pa, unsigned long size, bool writable);



int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);

virt/kvm/arm/vgic.c

+2 −1
Original line number Diff line number Diff line
@@ -1899,7 +1899,8 @@ int kvm_vgic_init(struct kvm *kvm) 
	}



	ret = kvm_phys_addr_ioremap(kvm, kvm->arch.vgic.vgic_cpu_base,

				    vgic->vcpu_base, KVM_VGIC_V2_CPU_SIZE);

				    vgic->vcpu_base, KVM_VGIC_V2_CPU_SIZE,

				    true);

	if (ret) {

		kvm_err("Unable to remap VGIC CPU to VCPU\n");

		goto out;