During boot, PAPR guests negotiate CPU model support with the
ibm,client-architecture-support mechanism. The logic to implement this in
qemu is very convoluted. This cleans it up to be cleaner, using the new
ppc_check_compat() call.
The new logic for choosing a compatibility mode is:
1. If the guest lists the CPU's real PVR as supported *AND* no
maximum compatibility mode has been requested on the command line
then we use "raw" mode - the CPU acts with full capabilities.
2. Otherwise, we pick the most recent compatibility mode which is
both supported by the CPU, and is advertised as supported by the
guest.
I think the original code approximated the same thing, but it's hard to be
sure, and I think it had some weird edge cases.
Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
---
hw/ppc/spapr_hcall.c | 107 +++++++++++++++++----------------------------------
hw/ppc/trace-events | 2 +-
2 files changed, 37 insertions(+), 72 deletions(-)
diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index d93f580..3bd6d06 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -895,98 +895,63 @@ static void do_set_compat(CPUState *cs, void *arg)
ppc_set_compat(cpu, s->compat_pvr, &s->err);
}
-#define get_compat_level(cpuver) ( \
- ((cpuver) == CPU_POWERPC_LOGICAL_2_05) ? 2050 : \
- ((cpuver) == CPU_POWERPC_LOGICAL_2_06) ? 2060 : \
- ((cpuver) == CPU_POWERPC_LOGICAL_2_06_PLUS) ? 2061 : \
- ((cpuver) == CPU_POWERPC_LOGICAL_2_07) ? 2070 : 0)
-
-static void cas_handle_compat_cpu(PowerPCCPUClass *pcc, uint32_t pvr,
- unsigned max_lvl, unsigned *compat_lvl,
- unsigned *compat_pvr)
-{
- unsigned lvl = get_compat_level(pvr);
- bool is205, is206, is207;
-
- if (!lvl) {
- return;
- }
-
- /* If it is a logical PVR, try to determine the highest level */
- is205 = (pcc->pcr_supported & PCR_COMPAT_2_05) &&
- (lvl == get_compat_level(CPU_POWERPC_LOGICAL_2_05));
- is206 = (pcc->pcr_supported & PCR_COMPAT_2_06) &&
- ((lvl == get_compat_level(CPU_POWERPC_LOGICAL_2_06)) ||
- (lvl == get_compat_level(CPU_POWERPC_LOGICAL_2_06_PLUS)));
- is207 = (pcc->pcr_supported & PCR_COMPAT_2_07) &&
- (lvl == get_compat_level(CPU_POWERPC_LOGICAL_2_07));
-
- if (is205 || is206 || is207) {
- if (!max_lvl) {
- /* User did not set the level, choose the highest */
- if (*compat_lvl <= lvl) {
- *compat_lvl = lvl;
- *compat_pvr = pvr;
- }
- } else if (max_lvl >= lvl) {
- /* User chose the level, don't set higher than this */
- *compat_lvl = lvl;
- *compat_pvr = pvr;
- }
- }
-}
-
-static target_ulong h_client_architecture_support(PowerPCCPU *cpu_,
+static target_ulong h_client_architecture_support(PowerPCCPU *cpu,
sPAPRMachineState *spapr,
target_ulong opcode,
target_ulong *args)
{
target_ulong list = ppc64_phys_to_real(args[0]);
target_ulong ov_table;
- PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu_);
CPUState *cs;
- bool cpu_match = false;
- unsigned old_compat_pvr = cpu_->compat_pvr;
- unsigned compat_lvl = 0, compat_pvr = 0;
- unsigned max_lvl = get_compat_level(cpu_->max_compat);
- int counter;
+ bool explicit_match = false; /* Matched the CPU's real PVR */
+ uint32_t max_compat = cpu->max_compat;
+ uint32_t best_compat = 0;
+ int i;
sPAPROptionVector *ov5_guest, *ov5_cas_old, *ov5_updates;
- /* Parse PVR list */
- for (counter = 0; counter < 512; ++counter) {
+ /*
+ * We scan the supplied table of PVRs looking for two things
+ * 1. Is our real CPU PVR in the list?
+ * 2. What's the "best" listed logical PVR
+ */
+ for (i = 0; i < 512; ++i) {
uint32_t pvr, pvr_mask;
- pvr_mask = ldl_be_phys(&address_space_memory, list);
- list += 4;
pvr = ldl_be_phys(&address_space_memory, list);
- list += 4;
-
- trace_spapr_cas_pvr_try(pvr);
- if (!max_lvl &&
- ((cpu_->env.spr[SPR_PVR] & pvr_mask) == (pvr & pvr_mask))) {
- cpu_match = true;
- compat_pvr = 0;
- } else if (pvr == cpu_->compat_pvr) {
- cpu_match = true;
- compat_pvr = cpu_->compat_pvr;
- } else if (!cpu_match) {
- cas_handle_compat_cpu(pcc, pvr, max_lvl, &compat_lvl, &compat_pvr);
- }
- /* Terminator record */
+ pvr_mask = ldl_be_phys(&address_space_memory, list + 4);
+ list += 8;
+
if (~pvr_mask & pvr) {
- break;
+ break; /* Terminator record */
}
+
+ if ((cpu->env.spr[SPR_PVR] & pvr_mask) == (pvr & pvr_mask)) {
+ explicit_match = true;
+ } else {
+ if (ppc_check_compat(cpu, pvr, best_compat, max_compat)) {
+ best_compat = pvr;
+ }
+ }
+ }
+
+ if (!max_compat && explicit_match) {
+ /* If the guest explicitly supports the CPU, *and* user hasn't
+ * requested a compatibility mode, use "raw" mode */
+ best_compat = 0;
+ } else if (best_compat == 0) {
+ /* Didn't find any supported compat modes */
+ /* FIXME: what's the right error here? */
+ return H_HARDWARE;
}
/* Parsing finished */
- trace_spapr_cas_pvr(cpu_->compat_pvr, cpu_match,
- compat_pvr, pcc->pcr_mask);
+ trace_spapr_cas_pvr(cpu->compat_pvr, explicit_match, best_compat);
/* Update CPUs */
- if (old_compat_pvr != compat_pvr) {
+ if (cpu->compat_pvr != best_compat) {
CPU_FOREACH(cs) {
SetCompatState s = {
- .compat_pvr = compat_pvr,
+ .compat_pvr = best_compat,
.err = NULL,
};
diff --git a/hw/ppc/trace-events b/hw/ppc/trace-events
index 2297ead..604ac92 100644
--- a/hw/ppc/trace-events
+++ b/hw/ppc/trace-events
@@ -15,7 +15,7 @@ spapr_cas_continue(unsigned long n) "Copy changes to the
guest: %ld bytes"
# hw/ppc/spapr_hcall.c
spapr_cas_pvr_try(uint32_t pvr) "%x"
-spapr_cas_pvr(uint32_t cur_pvr, bool cpu_match, uint32_t new_pvr, uint64_t
pcr) "current=%x, cpu_match=%u, new=%x, compat flags=%"PRIx64
+spapr_cas_pvr(uint32_t cur_pvr, bool explicit_match, uint32_t new_pvr)
"current=%x, explicit_match=%u, new=%x"
# hw/ppc/spapr_iommu.c
spapr_iommu_put(uint64_t liobn, uint64_t ioba, uint64_t tce, uint64_t ret)
"liobn=%"PRIx64" ioba=0x%"PRIx64" tce=0x%"PRIx64" ret=%"PRId64
--
2.7.4
