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| author | Alexander Graf <agraf@suse.de> | 2010-08-03 10:39:35 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-10-24 10:52:12 +0200 |
| commit | cbe487fac7fc016dbabbcbe83f11384e1803a56d (patch) | |
| tree | 7144ae2f0b5a920aba061c101b9a0ac8305d5e31 /arch/powerpc/kernel/kvm.c | |
| parent | df1bfa25d81f9451715ccbbb67551e0f792ceec8 (diff) | |
| download | linux-cbe487fac7fc016dbabbcbe83f11384e1803a56d.tar.gz | |
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.c | 60 |
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: |