[PATCH 16/27] Add desktop PowerPC specific emulation

Alexander Graf
2009-10-30T15:47:16Z

Little opcodes behave differently on desktop and embedded PowerPC cores.
In order to reflect those differences, let's add some #ifdef code to emulate.c.

We could probably also handle them in the core specific emulation files, but I
would prefer to reuse as much code as possible.

Signed-off-by: Alexander Graf <agraf-l3A5Bk7waGM@public.gmane.org>

---

v4 -> v5:

- use get_tb instead of mftb
- make ppc32 and ppc64 emulation share more code
---
arch/powerpc/kvm/emulate.c | 49 +++++++++++++++++++++++++++++++++++---------
1 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index 50d411d..1ec5e07 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -32,6 +32,7 @@
#include "trace.h"

#define OP_TRAP 3
+#define OP_TRAP_64 2

#define OP_31_XOP_LWZX 23
#define OP_31_XOP_LBZX 87
@@ -64,16 +65,36 @@
#define OP_STH 44
#define OP_STHU 45

+#ifdef CONFIG_PPC64
+static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
+{
+ return 1;
+}
+#else
+static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.tcr & TCR_DIE;
+}
+#endif
+
void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
{
unsigned long nr_jiffies;

- if (vcpu->arch.tcr & TCR_DIE) {
+#ifdef CONFIG_PPC64
+ /* POWER4+ triggers a dec interrupt if the value is < 0 */
+ if (vcpu->arch.dec & 0x80000000) {
+ del_timer(&vcpu->arch.dec_timer);
+ kvmppc_core_queue_dec(vcpu);
+ return;
+ }
+#endif
+ if (kvmppc_dec_enabled(vcpu)) {
/* The decrementer ticks at the same rate as the timebase, so
* that's how we convert the guest DEC value to the number of
* host ticks. */

- vcpu->arch.dec_jiffies = mftb();
+ vcpu->arch.dec_jiffies = get_tb();
nr_jiffies = vcpu->arch.dec / tb_ticks_per_jiffy;
mod_timer(&vcpu->arch.dec_timer,
get_jiffies_64() + nr_jiffies);
@@ -113,9 +134,15 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
/* this default type might be overwritten by subcategories */
kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);

+ pr_debug(KERN_INFO "Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
+
switch (get_op(inst)) {
case OP_TRAP:
+#ifdef CONFIG_PPC64
+ case OP_TRAP_64:
+#else
vcpu->arch.esr |= ESR_PTR;
+#endif
kvmppc_core_queue_program(vcpu);
advance = 0;
break;
@@ -190,17 +217,19 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
case SPRN_SRR1:
vcpu->arch.gpr[rt] = vcpu->arch.srr1; break;
case SPRN_PVR:
- vcpu->arch.gpr[rt] = mfspr(SPRN_PVR); break;
+ vcpu->arch.gpr[rt] = vcpu->arch.pvr; break;
case SPRN_PIR:
- vcpu->arch.gpr[rt] = mfspr(SPRN_PIR); break;
+ vcpu->arch.gpr[rt] = vcpu->vcpu_id; break;
+ case SPRN_MSSSR0:
+ vcpu->arch.gpr[rt] = 0; break;

/* Note: mftb and TBRL/TBWL are user-accessible, so
* the guest can always access the real TB anyways.
* In fact, we probably will never see these traps. */
case SPRN_TBWL:
- vcpu->arch.gpr[rt] = mftbl(); break;
+ vcpu->arch.gpr[rt] = get_tb() >> 32; break;
case SPRN_TBWU:
- vcpu->arch.gpr[rt] = mftbu(); break;
+ vcpu->arch.gpr[rt] = get_tb(); break;

case SPRN_SPRG0:
vcpu->arch.gpr[rt] = vcpu->arch.sprg0; break;
@@ -215,11 +244,9 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)

case SPRN_DEC:
{
- u64 jd = mftb() - vcpu->arch.dec_jiffies;
+ u64 jd = get_tb() - vcpu->arch.dec_jiffies;
vcpu->arch.gpr[rt] = vcpu->arch.dec - jd;
-#ifdef DEBUG_EMUL
- printk(KERN_INFO "mfDEC: %x - %llx = %lx\n", vcpu->arch.dec, jd, vcpu->arch.gpr[rt]);
-#endif
+ pr_debug(KERN_INFO "mfDEC: %x - %llx = %lx\n", vcpu->arch.dec, jd, vcpu->arch.gpr[rt]);
break;
}
default:
@@ -271,6 +298,8 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
case SPRN_TBWL: break;
case SPRN_TBWU: break;

+ case SPRN_MSSSR0: break;
+
case SPRN_DEC:
vcpu->arch.dec = vcpu->arch.gpr[rs];
kvmppc_emulate_dec(vcpu);
--
1.6.0.2