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

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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: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This commit is contained in:
Ard Biesheuvel 2014-09-17 14:56:18 -07:00 committed by Christoffer Dall
parent 37b544087e
commit c40f2f8ff8
4 changed files with 8 additions and 4 deletions
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2
arch/arm/include/asm/kvm_mmu.h
View file

@ -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);

5
arch/arm/kvm/mmu.c
View file

@ -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;

2
arch/arm64/include/asm/kvm_mmu.h
View file

@ -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);

3
virt/kvm/arm/vgic.c
View file

@ -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;