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Diffstat (limited to 'arch/mips/kvm/dyntrans.c')
-rw-r--r--arch/mips/kvm/dyntrans.c52
1 files changed, 31 insertions, 21 deletions
diff --git a/arch/mips/kvm/dyntrans.c b/arch/mips/kvm/dyntrans.c
index 010cef240688..f8e772564d74 100644
--- a/arch/mips/kvm/dyntrans.c
+++ b/arch/mips/kvm/dyntrans.c
@@ -13,6 +13,7 @@
#include <linux/err.h>
#include <linux/highmem.h>
#include <linux/kvm_host.h>
+#include <linux/uaccess.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/bootmem.h>
@@ -29,28 +30,37 @@
static int kvm_mips_trans_replace(struct kvm_vcpu *vcpu, u32 *opc,
union mips_instruction replace)
{
- unsigned long paddr, flags;
- void *vaddr;
-
- if (KVM_GUEST_KSEGX((unsigned long)opc) == KVM_GUEST_KSEG0) {
- 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));
- __local_flush_icache_user_range((unsigned long)opc,
- (unsigned long)opc + 32);
- local_irq_restore(flags);
- } else {
- kvm_err("%s: Invalid address: %p\n", __func__, opc);
- return -EFAULT;
+ unsigned long vaddr = (unsigned long)opc;
+ int err;
+
+retry:
+ /* The GVA page table is still active so use the Linux TLB handlers */
+ kvm_trap_emul_gva_lockless_begin(vcpu);
+ err = put_user(replace.word, opc);
+ kvm_trap_emul_gva_lockless_end(vcpu);
+
+ if (unlikely(err)) {
+ /*
+ * We write protect clean pages in GVA page table so normal
+ * Linux TLB mod handler doesn't silently dirty the page.
+ * Its also possible we raced with a GVA invalidation.
+ * Try to force the page to become dirty.
+ */
+ err = kvm_trap_emul_gva_fault(vcpu, vaddr, true);
+ if (unlikely(err)) {
+ kvm_info("%s: Address unwriteable: %p\n",
+ __func__, opc);
+ return -EFAULT;
+ }
+
+ /*
+ * Try again. This will likely trigger a TLB refill, which will
+ * fetch the new dirty entry from the GVA page table, which
+ * should then succeed.
+ */
+ goto retry;
}
+ __local_flush_icache_user_range(vaddr, vaddr + 4);
return 0;
}

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