KVM: PPC: Fix dcbz emulation

[~andy/linux] / arch / powerpc / kvm / book3s.c

diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index d2b3dabe2dc39354e6c96356f2b07d634c7aa42f..ed57584963720fde842d155f3d33c4dfd64009bf 100644 (file)
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -29,6 +29,7 @@
 #include <linux/gfp.h>
 #include <linux/sched.h>
 #include <linux/vmalloc.h>
+#include <linux/highmem.h>
 
 #define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
 
@@ -369,34 +370,29 @@ void kvmppc_set_pvr(struct kvm_vcpu *vcpu, u32 pvr)
  */
 static void kvmppc_patch_dcbz(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
 {
-       bool touched = false;
-       hva_t hpage;
+       struct page *hpage;
+       u64 hpage_offset;
        u32 *page;
        int i;
 
-       hpage = gfn_to_hva(vcpu->kvm, pte->raddr >> PAGE_SHIFT);
-       if (kvm_is_error_hva(hpage))
+       hpage = gfn_to_page(vcpu->kvm, pte->raddr >> PAGE_SHIFT);
+       if (is_error_page(hpage))
                return;
 
-       hpage |= pte->raddr & ~PAGE_MASK;
-       hpage &= ~0xFFFULL;
-
-       page = vmalloc(HW_PAGE_SIZE);
-
-       if (copy_from_user(page, (void __user *)hpage, HW_PAGE_SIZE))
-               goto out;
+       hpage_offset = pte->raddr & ~PAGE_MASK;
+       hpage_offset &= ~0xFFFULL;
+       hpage_offset /= 4;
 
-       for (i=0; i < HW_PAGE_SIZE / 4; i++)
-               if ((page[i] & 0xff0007ff) == INS_DCBZ) {
-                       page[i] &= 0xfffffff7; // reserved instruction, so we trap
-                       touched = true;
-               }
+       get_page(hpage);
+       page = kmap_atomic(hpage, KM_USER0);
 
-       if (touched)
-               copy_to_user((void __user *)hpage, page, HW_PAGE_SIZE);
+       /* patch dcbz into reserved instruction, so we trap */
+       for (i=hpage_offset; i < hpage_offset + (HW_PAGE_SIZE / 4); i++)
+               if ((page[i] & 0xff0007ff) == INS_DCBZ)
+                       page[i] &= 0xfffffff7;
 
-out:
-       vfree(page);
+       kunmap_atomic(page, KM_USER0);
+       put_page(hpage);
 }
 
 static int kvmppc_xlate(struct kvm_vcpu *vcpu, ulong eaddr, bool data,
@@ -449,30 +445,21 @@ int kvmppc_st(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr,
              bool data)
 {
        struct kvmppc_pte pte;
-       hva_t hva = *eaddr;
 
        vcpu->stat.st++;
 
        if (kvmppc_xlate(vcpu, *eaddr, data, &pte))
-               goto nopte;
+               return -ENOENT;
 
        *eaddr = pte.raddr;
 
-       hva = kvmppc_pte_to_hva(vcpu, &pte, false);
-       if (kvm_is_error_hva(hva))
-               goto mmio;
+       if (!pte.may_write)
+               return -EPERM;
 
-       if (copy_to_user((void __user *)hva, ptr, size)) {
-               printk(KERN_INFO "kvmppc_st at 0x%lx failed\n", hva);
-               goto mmio;
-       }
+       if (kvm_write_guest(vcpu->kvm, pte.raddr, ptr, size))
+               return EMULATE_DO_MMIO;
 
        return EMULATE_DONE;
-
-nopte:
-       return -ENOENT;
-mmio:
-       return EMULATE_DO_MMIO;
 }
 
 int kvmppc_ld(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr,
@@ -787,6 +774,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
                         *     that no guest that needs the dcbz hack does NX.
                         */
                        kvmppc_mmu_pte_flush(vcpu, vcpu->arch.pc, ~0xFFFULL);
+                       r = RESUME_GUEST;
                } else {
                        vcpu->arch.msr |= vcpu->arch.shadow_srr1 & 0x58000000;
                        kvmppc_book3s_queue_irqprio(vcpu, exit_nr);