From 28cc5bd568745a58bb06291ac336d06b66c66dff Mon Sep 17 00:00:00 2001 From: James Hogan Date: Fri, 8 Jul 2016 11:53:22 +0100 Subject: [PATCH] MIPS: KVM: Use kmap instead of CKSEG0ADDR() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini --- arch/mips/kvm/dyntrans.c | 17 +++++++++++------ arch/mips/kvm/mmu.c | 7 ++++++- 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 #include +#include #include #include #include @@ -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 */ +#include #include #include @@ -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;