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authorAlexander Graf <agraf@suse.de>2010-07-29 14:48:05 +0200
committerAvi Kivity <avi@redhat.com>2010-10-24 10:50:56 +0200
commit7810927760a0d16d7a41be4dab895fbbf9445bc0 (patch)
treef215dd900d26d691c05f9b48233b7ef910b4fb1d /arch/powerpc/kernel/kvm.c
parent819a63dc792b0888edd3eda306a9e1e049dcbb1c (diff)
KVM: PPC: PV mtmsrd L=0 and mtmsr
There is also a form of mtmsr where all bits need to be addressed. While the PPC64 Linux kernel behaves resonably well here, on PPC32 we do not have an L=1 form. It does mtmsr even for simple things like only changing EE. So we need to hook into that one as well and check for a mask of bits that we deem safe to change from within guest context. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/powerpc/kernel/kvm.c')
-rw-r--r--arch/powerpc/kernel/kvm.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index 717ab0dded2..8ac57e2c52f 100644
--- a/arch/powerpc/kernel/kvm.c
+++ b/arch/powerpc/kernel/kvm.c
@@ -63,7 +63,9 @@
#define KVM_INST_MTSPR_DSISR 0x7c1203a6
#define KVM_INST_TLBSYNC 0x7c00046c
+#define KVM_INST_MTMSRD_L0 0x7c000164
#define KVM_INST_MTMSRD_L1 0x7c010164
+#define KVM_INST_MTMSR 0x7c000124
static bool kvm_patching_worked = true;
static char kvm_tmp[1024 * 1024];
@@ -176,6 +178,49 @@ static void kvm_patch_ins_mtmsrd(u32 *inst, u32 rt)
kvm_patch_ins_b(inst, distance_start);
}
+extern u32 kvm_emulate_mtmsr_branch_offs;
+extern u32 kvm_emulate_mtmsr_reg1_offs;
+extern u32 kvm_emulate_mtmsr_reg2_offs;
+extern u32 kvm_emulate_mtmsr_reg3_offs;
+extern u32 kvm_emulate_mtmsr_orig_ins_offs;
+extern u32 kvm_emulate_mtmsr_len;
+extern u32 kvm_emulate_mtmsr[];
+
+static void kvm_patch_ins_mtmsr(u32 *inst, u32 rt)
+{
+ u32 *p;
+ int distance_start;
+ int distance_end;
+ ulong next_inst;
+
+ p = kvm_alloc(kvm_emulate_mtmsr_len * 4);
+ if (!p)
+ return;
+
+ /* Find out where we are and put everything there */
+ distance_start = (ulong)p - (ulong)inst;
+ next_inst = ((ulong)inst + 4);
+ distance_end = next_inst - (ulong)&p[kvm_emulate_mtmsr_branch_offs];
+
+ /* Make sure we only write valid b instructions */
+ if (distance_start > KVM_INST_B_MAX) {
+ kvm_patching_worked = false;
+ return;
+ }
+
+ /* Modify the chunk to fit the invocation */
+ memcpy(p, kvm_emulate_mtmsr, kvm_emulate_mtmsr_len * 4);
+ p[kvm_emulate_mtmsr_branch_offs] |= distance_end & KVM_INST_B_MASK;
+ p[kvm_emulate_mtmsr_reg1_offs] |= rt;
+ p[kvm_emulate_mtmsr_reg2_offs] |= rt;
+ p[kvm_emulate_mtmsr_reg3_offs] |= rt;
+ p[kvm_emulate_mtmsr_orig_ins_offs] = *inst;
+ flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsr_len * 4);
+
+ /* Patch the invocation */
+ kvm_patch_ins_b(inst, distance_start);
+}
+
static void kvm_map_magic_page(void *data)
{
kvm_hypercall2(KVM_HC_PPC_MAP_MAGIC_PAGE,
@@ -256,6 +301,12 @@ static void kvm_check_ins(u32 *inst)
if (get_rt(inst_rt) < 30)
kvm_patch_ins_mtmsrd(inst, inst_rt);
break;
+ case KVM_INST_MTMSR:
+ case KVM_INST_MTMSRD_L0:
+ /* We use r30 and r31 during the hook */
+ if (get_rt(inst_rt) < 30)
+ kvm_patch_ins_mtmsr(inst, inst_rt);
+ break;
}
switch (_inst) {