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authorAlexander Graf <agraf@suse.de>2010-08-03 10:39:35 +0200
committerAvi Kivity <avi@redhat.com>2010-10-24 10:52:12 +0200
commitcbe487fac7fc016dbabbcbe83f11384e1803a56d (patch)
tree7144ae2f0b5a920aba061c101b9a0ac8305d5e31 /arch/powerpc/kernel/kvm.c
parentKVM: PPC: Put segment registers in shared page (diff)
downloadlinux-cbe487fac7fc016dbabbcbe83f11384e1803a56d.tar.xz
linux-cbe487fac7fc016dbabbcbe83f11384e1803a56d.zip
KVM: PPC: Add mtsrin PV code
This is the guest side of the mtsr acceleration. Using this a guest can now call mtsrin with almost no overhead as long as it ensures that it only uses it with (MSR_IR|MSR_DR) == 0. Linux does that, so we're good. Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'arch/powerpc/kernel/kvm.c')
-rw-r--r--arch/powerpc/kernel/kvm.c60
1 files changed, 60 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index 226882fe85a6..c8bab24ff8ac 100644
--- a/arch/powerpc/kernel/kvm.c
+++ b/arch/powerpc/kernel/kvm.c
@@ -42,6 +42,7 @@
#define KVM_INST_B_MAX 0x01ffffff
#define KVM_MASK_RT 0x03e00000
+#define KVM_MASK_RB 0x0000f800
#define KVM_INST_MFMSR 0x7c0000a6
#define KVM_INST_MFSPR_SPRG0 0x7c1042a6
#define KVM_INST_MFSPR_SPRG1 0x7c1142a6
@@ -69,6 +70,8 @@
#define KVM_INST_WRTEEI_0 0x7c000146
#define KVM_INST_WRTEEI_1 0x7c008146
+#define KVM_INST_MTSRIN 0x7c0001e4
+
static bool kvm_patching_worked = true;
static char kvm_tmp[1024 * 1024];
static int kvm_tmp_index;
@@ -264,6 +267,51 @@ static void kvm_patch_ins_wrteei(u32 *inst)
#endif
+#ifdef CONFIG_PPC_BOOK3S_32
+
+extern u32 kvm_emulate_mtsrin_branch_offs;
+extern u32 kvm_emulate_mtsrin_reg1_offs;
+extern u32 kvm_emulate_mtsrin_reg2_offs;
+extern u32 kvm_emulate_mtsrin_orig_ins_offs;
+extern u32 kvm_emulate_mtsrin_len;
+extern u32 kvm_emulate_mtsrin[];
+
+static void kvm_patch_ins_mtsrin(u32 *inst, u32 rt, u32 rb)
+{
+ u32 *p;
+ int distance_start;
+ int distance_end;
+ ulong next_inst;
+
+ p = kvm_alloc(kvm_emulate_mtsrin_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_mtsrin_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_mtsrin, kvm_emulate_mtsrin_len * 4);
+ p[kvm_emulate_mtsrin_branch_offs] |= distance_end & KVM_INST_B_MASK;
+ p[kvm_emulate_mtsrin_reg1_offs] |= (rb << 10);
+ p[kvm_emulate_mtsrin_reg2_offs] |= rt;
+ p[kvm_emulate_mtsrin_orig_ins_offs] = *inst;
+ flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtsrin_len * 4);
+
+ /* Patch the invocation */
+ kvm_patch_ins_b(inst, distance_start);
+}
+
+#endif
+
static void kvm_map_magic_page(void *data)
{
u32 *features = data;
@@ -360,6 +408,18 @@ static void kvm_check_ins(u32 *inst, u32 features)
break;
}
+ switch (inst_no_rt & ~KVM_MASK_RB) {
+#ifdef CONFIG_PPC_BOOK3S_32
+ case KVM_INST_MTSRIN:
+ if (features & KVM_MAGIC_FEAT_SR) {
+ u32 inst_rb = _inst & KVM_MASK_RB;
+ kvm_patch_ins_mtsrin(inst, inst_rt, inst_rb);
+ }
+ break;
+ break;
+#endif
+ }
+
switch (_inst) {
#ifdef CONFIG_BOOKE
case KVM_INST_WRTEEI_0: