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authorJames Hogan <james.hogan@imgtec.com>2016-08-19 16:09:47 +0200
committerJames Hogan <james.hogan@imgtec.com>2016-09-08 19:29:54 +0200
commitd5888477d31c64dba9264fbb33cfa9b066f071d0 (patch)
treefdc2e5eb025f4f977b78f78ef4e76e786781886d /arch/mips/kvm/trap_emul.c
parentKVM: MIPS: Override HVA error values for EVA (diff)
downloadlinux-d5888477d31c64dba9264fbb33cfa9b066f071d0.tar.xz
linux-d5888477d31c64dba9264fbb33cfa9b066f071d0.zip
KVM: MIPS: Emulate MMIO via TLB miss for EVA
MIPS Enhanced Virtual Addressing (EVA) allows the virtual memory segments to be rearranged such that the KSeg0/KSeg1 segments are accessible TLB mapped to user mode, which would trigger a TLB Miss exception (due to lack of TLB mappings) instead of an Address Error exception. Update the TLB Miss handling similar to Address Error handling for guest MMIO emulation. 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
Diffstat (limited to 'arch/mips/kvm/trap_emul.c')
-rw-r--r--arch/mips/kvm/trap_emul.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
index 091553942bcb..3a5484f9aa50 100644
--- a/arch/mips/kvm/trap_emul.c
+++ b/arch/mips/kvm/trap_emul.c
@@ -175,6 +175,24 @@ static int kvm_trap_emul_handle_tlb_miss(struct kvm_vcpu *vcpu, bool store)
run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
ret = RESUME_HOST;
}
+ } else if (KVM_GUEST_KERNEL_MODE(vcpu)
+ && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
+ /*
+ * With EVA we may get a TLB exception instead of an address
+ * error when the guest performs MMIO to KSeg1 addresses.
+ */
+ kvm_debug("Emulate %s MMIO space\n",
+ store ? "Store to" : "Load from");
+ er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
+ if (er == EMULATE_FAIL) {
+ kvm_err("Emulate %s MMIO space failed\n",
+ store ? "Store to" : "Load from");
+ run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ ret = RESUME_HOST;
+ } else {
+ run->exit_reason = KVM_EXIT_MMIO;
+ ret = RESUME_HOST;
+ }
} else {
kvm_err("Illegal TLB %s fault address , cause %#x, PC: %p, BadVaddr: %#lx\n",
store ? "ST" : "LD", cause, opc, badvaddr);