spapr: Implement processor compatibility in ibm, client-architecture-support
Modern Linux kernels support last POWERPC CPUs so when a kernel boots,
in most cases it can find a matching cpu_spec in the kernel's cpu_specs
list. However if the kernel is quite old, it may be missing a definition
of the actual CPU. To provide an ability for old kernels to work on modern
hardware, a Processor Compatibility Mode has been introduced
by the PowerISA specification.
>From the hardware prospective, it is supported by the Processor
Compatibility Register (PCR) which is defined in PowerISA. The register
enables one of the compatibility modes (2.05/2.06/2.07).
Since PCR is a hypervisor privileged register and cannot be
directly accessed from the guest, the mode selection is done via
ibm,client-architecture-support (CAS) RTAS call using which the guest
specifies what "raw" and "architected" CPU versions it supports.
QEMU works out the best match, changes a "cpu-version" property of
every CPU and notifies the guest about the change by setting these
properties in the buffer passed as a response on a custom H_CAS hypercall.
This implements ibm,client-architecture-support parameters parsing
(now only for PVRs) and cooks the device tree diff with new values for
"cpu-version", "ibm,ppc-interrupt-server#s" and
"ibm,ppc-interrupt-server#s" properties.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/trace-events b/trace-events
index 9f12843..c3ade1c 100644
--- a/trace-events
+++ b/trace-events
@@ -1193,6 +1193,10 @@
spapr_cas_failed(unsigned long n) "DT diff buffer is too small: %ld bytes"
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
+
# 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
spapr_iommu_get(uint64_t liobn, uint64_t ioba, uint64_t ret, uint64_t tce) "liobn=%"PRIx64" ioba=0x%"PRIx64" ret=%"PRId64" tce=0x%"PRIx64