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authorJames Hogan <james.hogan@imgtec.com>2016-07-08 11:53:22 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2016-08-01 18:42:22 +0200
commit28cc5bd568745a58bb06291ac336d06b66c66dff (patch)
treed8c1dd5dd137177910f127f125e0e402be3ffded /arch
parentcfacaced0cce20859de25b61d672edeb9789a1e9 (diff)
MIPS: KVM: Use kmap instead of CKSEG0ADDR()
There are several unportable uses of CKSEG0ADDR() in MIPS KVM, which implicitly assume that a host physical address will be in the low 512MB of the physical address space (accessible in KSeg0). These assumptions don't hold for highmem or on 64-bit kernels. When interpreting the guest physical address when reading or overwriting a trapping instruction, use kmap_atomic() to get a usable virtual address to access guest memory, which is portable to 64-bit and highmem kernels. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/kvm/dyntrans.c17
-rw-r--r--arch/mips/kvm/mmu.c7
2 files changed, 17 insertions, 7 deletions
diff --git a/arch/mips/kvm/dyntrans.c b/arch/mips/kvm/dyntrans.c
index 91ebd2b6034f..9a16ba2cb487 100644
--- a/arch/mips/kvm/dyntrans.c
+++ b/arch/mips/kvm/dyntrans.c
@@ -11,6 +11,7 @@
#include <linux/errno.h>
#include <linux/err.h>
+#include <linux/highmem.h>
#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
@@ -29,14 +30,18 @@
static int kvm_mips_trans_replace(struct kvm_vcpu *vcpu, u32 *opc,
union mips_instruction replace)
{
- unsigned long kseg0_opc, flags;
+ unsigned long paddr, flags;
+ void *vaddr;
if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) {
- kseg0_opc =
- CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
- (vcpu, (unsigned long) opc));
- memcpy((void *)kseg0_opc, (void *)&replace, sizeof(u32));
- local_flush_icache_range(kseg0_opc, kseg0_opc + 32);
+ paddr = kvm_mips_translate_guest_kseg0_to_hpa(vcpu,
+ (unsigned long)opc);
+ vaddr = kmap_atomic(pfn_to_page(PHYS_PFN(paddr)));
+ vaddr += paddr & ~PAGE_MASK;
+ memcpy(vaddr, (void *)&replace, sizeof(u32));
+ local_flush_icache_range((unsigned long)vaddr,
+ (unsigned long)vaddr + 32);
+ kunmap_atomic(vaddr);
} else if (KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
local_irq_save(flags);
memcpy((void *)opc, (void *)&replace, sizeof(u32));
diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index ecead748de04..57319ee57c4f 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -9,6 +9,7 @@
* Authors: Sanjay Lal <sanjayl@kymasys.com>
*/
+#include <linux/highmem.h>
#include <linux/kvm_host.h>
#include <asm/mmu_context.h>
@@ -330,6 +331,7 @@ u32 kvm_get_inst(u32 *opc, struct kvm_vcpu *vcpu)
struct mips_coproc *cop0 = vcpu->arch.cop0;
unsigned long paddr, flags, vpn2, asid;
unsigned long va = (unsigned long)opc;
+ void *vaddr;
u32 inst;
int index;
@@ -360,7 +362,10 @@ u32 kvm_get_inst(u32 *opc, struct kvm_vcpu *vcpu)
local_irq_restore(flags);
} else if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {
paddr = kvm_mips_translate_guest_kseg0_to_hpa(vcpu, va);
- inst = *(u32 *) CKSEG0ADDR(paddr);
+ vaddr = kmap_atomic(pfn_to_page(PHYS_PFN(paddr)));
+ vaddr += paddr & ~PAGE_MASK;
+ inst = *(u32 *)vaddr;
+ kunmap_atomic(vaddr);
} else {
kvm_err("%s: illegal address: %p\n", __func__, opc);
return KVM_INVALID_INST;