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raw | patch | inline | side by side (parent: d6f5e87)
author | Christoffer Dall <christoffer.dall@linaro.org> | |
Thu, 27 Nov 2014 09:35:03 +0000 (10:35 +0100) | ||
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
Sat, 4 Jul 2015 02:49:07 +0000 (19:49 -0700) |
commit 957db105c99792ae8ef61ffc9ae77d910f6471da upstream.
Introduce a new function to unmap user RAM regions in the stage2 page
tables. This is needed on reboot (or when the guest turns off the MMU)
to ensure we fault in pages again and make the dcache, RAM, and icache
coherent.
Using unmap_stage2_range for the whole guest physical range does not
work, because that unmaps IO regions (such as the GIC) which will not be
recreated or in the best case faulted in on a page-by-page basis.
Call this function on secondary and subsequent calls to the
KVM_ARM_VCPU_INIT ioctl so that a reset VCPU will detect the guest
Stage-1 MMU is off when faulting in pages and make the caches coherent.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce a new function to unmap user RAM regions in the stage2 page
tables. This is needed on reboot (or when the guest turns off the MMU)
to ensure we fault in pages again and make the dcache, RAM, and icache
coherent.
Using unmap_stage2_range for the whole guest physical range does not
work, because that unmaps IO regions (such as the GIC) which will not be
recreated or in the best case faulted in on a page-by-page basis.
Call this function on secondary and subsequent calls to the
KVM_ARM_VCPU_INIT ioctl so that a reset VCPU will detect the guest
Stage-1 MMU is off when faulting in pages and make the caches coherent.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/arm/include/asm/kvm_mmu.h | patch | blob | history | |
arch/arm/kvm/arm.c | patch | blob | history | |
arch/arm/kvm/mmu.c | patch | blob | history | |
arch/arm64/include/asm/kvm_mmu.h | patch | blob | history |
index 630869eb4d8876e22b992efb2c0e690790e38aaa..9f7923193cda90f1a43fcbe20f3c433e1daa7b8f 100644 (file)
void free_boot_hyp_pgd(void);
void free_hyp_pgds(void);
+void stage2_unmap_vm(struct kvm *kvm);
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,
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 077f82d040862941f6992e59fd7d4ff1d8314a4b..039df03069d399dee56f7ea50162d6817dbaa772 100644 (file)
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
if (ret)
return ret;
+ /*
+ * Ensure a rebooted VM will fault in RAM pages and detect if the
+ * guest MMU is turned off and flush the caches as needed.
+ */
+ if (vcpu->arch.has_run_once)
+ stage2_unmap_vm(vcpu->kvm);
+
vcpu_reset_hcr(vcpu);
/*
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 5b12c4990c902a4608f765bf98bc99574ba1e75e..524b4b57f6504f42b814c7c9923bfd6d2fc0f8fb 100644 (file)
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
unmap_range(kvm, kvm->arch.pgd, start, size);
}
+static void stage2_unmap_memslot(struct kvm *kvm,
+ struct kvm_memory_slot *memslot)
+{
+ hva_t hva = memslot->userspace_addr;
+ phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
+ phys_addr_t size = PAGE_SIZE * memslot->npages;
+ hva_t reg_end = hva + size;
+
+ /*
+ * A memory region could potentially cover multiple VMAs, and any holes
+ * between them, so iterate over all of them to find out if we should
+ * unmap any of them.
+ *
+ * +--------------------------------------------+
+ * +---------------+----------------+ +----------------+
+ * | : VMA 1 | VMA 2 | | VMA 3 : |
+ * +---------------+----------------+ +----------------+
+ * | memory region |
+ * +--------------------------------------------+
+ */
+ do {
+ struct vm_area_struct *vma = find_vma(current->mm, hva);
+ hva_t vm_start, vm_end;
+
+ if (!vma || vma->vm_start >= reg_end)
+ break;
+
+ /*
+ * Take the intersection of this VMA with the memory region
+ */
+ vm_start = max(hva, vma->vm_start);
+ vm_end = min(reg_end, vma->vm_end);
+
+ if (!(vma->vm_flags & VM_PFNMAP)) {
+ gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
+ unmap_stage2_range(kvm, gpa, vm_end - vm_start);
+ }
+ hva = vm_end;
+ } while (hva < reg_end);
+}
+
+/**
+ * stage2_unmap_vm - Unmap Stage-2 RAM mappings
+ * @kvm: The struct kvm pointer
+ *
+ * Go through the memregions and unmap any reguler RAM
+ * backing memory already mapped to the VM.
+ */
+void stage2_unmap_vm(struct kvm *kvm)
+{
+ struct kvm_memslots *slots;
+ struct kvm_memory_slot *memslot;
+ int idx;
+
+ idx = srcu_read_lock(&kvm->srcu);
+ spin_lock(&kvm->mmu_lock);
+
+ slots = kvm_memslots(kvm);
+ kvm_for_each_memslot(memslot, slots)
+ stage2_unmap_memslot(kvm, memslot);
+
+ spin_unlock(&kvm->mmu_lock);
+ srcu_read_unlock(&kvm->srcu, idx);
+}
+
/**
* kvm_free_stage2_pgd - free all stage-2 tables
* @kvm: The KVM struct pointer for the VM.
index a030d163840bf02e9eccd4828f54743dc4b8363b..0d51874c838f42c7afdab5485d3c1a094ef69049 100644 (file)
void free_boot_hyp_pgd(void);
void free_hyp_pgds(void);
+void stage2_unmap_vm(struct kvm *kvm);
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,