Add the necessary infrastructure to handle MMU notifiers on KVM/ARM.
As we don't have shadow page tables, the implementation is actually very
simple. The only supported operation is kvm_unmap_hva(), where we remove
the HVA from the 2nd stage translation. All other hooks are NOPs.
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm/include/asm/kvm_asm.h | 4 ++++
arch/arm/include/asm/kvm_host.h | 19 +++++++++++++++++++
arch/arm/kvm/Kconfig | 3 ++-
arch/arm/kvm/arm.c | 4 ++--
arch/arm/kvm/interrupts.S | 23 +++++++++++++++++++++++
arch/arm/kvm/mmu.c | 21 ++++++++++++++++++---
6 files changed, 68 insertions(+), 6 deletions(-)
diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
index 89c318ea..f933886 100644
--- a/arch/arm/include/asm/kvm_asm.h
+++ b/arch/arm/include/asm/kvm_asm.h
@@ -36,6 +36,7 @@ asm(".equ SMCHYP_HVBAR_W, 0xfffffff0");
#endif /* __ASSEMBLY__ */
#ifndef __ASSEMBLY__
+struct kvm;
struct kvm_vcpu;
extern char __kvm_hyp_init[];
@@ -46,6 +47,9 @@ extern char __kvm_hyp_vector_end[];
extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
extern char __kvm_vcpu_run_end[];
+
+extern void __kvm_tlb_flush_vmid(struct kvm *kvm);
+extern char __kvm_hyp_code_end[];
#endif
#endif /* __ARM_KVM_ASM_H__ */
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 555a6f1..1c0c68b 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -109,4 +109,23 @@ struct kvm_vm_stat {
struct kvm_vcpu_stat {
};
+#define KVM_ARCH_WANT_MMU_NOTIFIER
+struct kvm;
+int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
+
+/* We do not have shadow page tables, hence the empty hooks */
+static inline int kvm_age_hva(struct kvm *kvm, unsigned long hva)
+{
+ return 0;
+}
+
+static inline int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
+{
+ return 0;
+}
+
+static inline void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
+{
+}
+
#endif /* __ARM_KVM_HOST_H__ */
diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
index ccabbb3..f943dff 100644
--- a/arch/arm/kvm/Kconfig
+++ b/arch/arm/kvm/Kconfig
@@ -35,7 +35,8 @@ config KVM_ARM_HOST
bool "KVM host support for ARM cpus."
depends on KVM
depends on MMU
- depends on CPU_V7 || ARM_VIRT_EXT
+ depends on ARM_VIRT_EXT
+ select MMU_NOTIFIER
---help---
Provides host support for ARM processors.
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 14ccc4d..602e087 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -636,9 +636,9 @@ static int init_hyp_mode(void)
* Map the world-switch code
*/
err = create_hyp_mappings(kvm_hyp_pgd,
- __kvm_vcpu_run, __kvm_vcpu_run_end);
+ __kvm_vcpu_run, __kvm_hyp_code_end);
if (err) {
- kvm_err(err, "Cannot map world-switch code");
+ kvm_err(err, "Cannot map hyp mode code");
goto out_free_mappings;
}
diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
index fbc26ca..c3d7adb 100644
--- a/arch/arm/kvm/interrupts.S
+++ b/arch/arm/kvm/interrupts.S
@@ -356,6 +356,29 @@ THUMB( orr lr, lr, #1)
__kvm_vcpu_run_end:
.globl __kvm_vcpu_run_end
+ENTRY(__kvm_tlb_flush_vmid)
+ hvc #0 @ Switch to Hyp mode
+ push {r2, r3}
+
+ ldrd r2, r3, [r0, #KVM_VTTBR]
+ mcrr p15, 6, r2, r3, c2 @ Write VTTBR
+ isb
+ mcr p15, 0, r0, c8, c7, 0 @ TBLIALL
+ dsb
+ isb
+ mov r2, #0
+ mov r3, #0
+ mcrr p15, 6, r2, r3, c2 @ Back to VMID #0
+ isb
+
+ pop {r2, r3}
+ hvc #0 @ Back to SVC
+ mov pc, lr
+ENDPROC(__kvm_tlb_flush_vmid)
+
+__kvm_hyp_code_end:
+ .globl __kvm_hyp_code_end
+
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ Hypervisor exception vector and handlers
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index baeb8a1..0e4480b 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -245,12 +245,12 @@ void kvm_free_stage2_pgd(struct kvm *kvm)
kvm->arch.pgd = NULL;
}
-static int __user_mem_abort(struct kvm *kvm, phys_addr_t addr, pfn_t pfn)
+static int stage2_set_pte(struct kvm *kvm, phys_addr_t addr, pte_t new_pte)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
- pte_t *pte, new_pte;
+ pte_t *pte;
/* Create 2nd stage page table mapping - Level 1 */
pgd = kvm->arch.pgd + pgd_index(addr);
@@ -279,12 +279,18 @@ static int __user_mem_abort(struct kvm *kvm, phys_addr_t addr, pfn_t pfn)
pte = pte_offset_kernel(pmd, addr);
/* Create 2nd stage page table mapping - Level 3 */
- new_pte = pfn_pte(pfn, PAGE_KVM_GUEST);
set_pte_ext(pte, new_pte, 0);
return 0;
}
+static int __user_mem_abort(struct kvm *kvm, phys_addr_t addr, pfn_t pfn)
+{
+ pte_t new_pte = pfn_pte(pfn, PAGE_KVM_GUEST);
+
+ return stage2_set_pte(kvm, addr, new_pte);
+}
+
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
gfn_t gfn, struct kvm_memory_slot *memslot)
{
@@ -510,3 +516,12 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
return user_mem_abort(vcpu, fault_ipa, gfn, memslot);
}
+
+static const pte_t null_pte;
+
+int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
+{
+ int ret = stage2_set_pte(kvm, (phys_addr_t)hva, null_pte);
+ __kvm_tlb_flush_vmid(kvm);
+ return ret;
+}
--
1.7.3.4
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