From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33441) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WlIvk-0000gp-L8 for qemu-devel@nongnu.org; Fri, 16 May 2014 10:16:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WlIve-0003lP-Af for qemu-devel@nongnu.org; Fri, 16 May 2014 10:16:12 -0400 Message-ID: <53761DA4.8080000@suse.de> Date: Fri, 16 May 2014 16:16:04 +0200 From: Alexander Graf MIME-Version: 1.0 References: <1400153291-20759-1-git-send-email-aik@ozlabs.ru> <1400153291-20759-9-git-send-email-aik@ozlabs.ru> In-Reply-To: <1400153291-20759-9-git-send-email-aik@ozlabs.ru> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 8/9] spapr: Implement processor compatibility in ibm, client-architecture-support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy , qemu-devel@nongnu.org Cc: qemu-ppc@nongnu.org On 15.05.14 13:28, Alexey Kardashevskiy wrote: > 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 > 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. > > Signed-off-by: Alexey Kardashevskiy > --- > hw/ppc/spapr.c | 40 +++++++++++++++++++++++++ > hw/ppc/spapr_hcall.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > trace-events | 5 ++++ > 3 files changed, 128 insertions(+) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index a2c9106..a0882a1 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -35,6 +35,7 @@ > #include "kvm_ppc.h" > #include "mmu-hash64.h" > #include "cpu-models.h" > +#include "qom/cpu.h" > > #include "hw/boards.h" > #include "hw/ppc/ppc.h" > @@ -592,11 +593,50 @@ int spapr_h_cas_compose_response(target_ulong addr, target_ulong size) > { > void *fdt; > sPAPRDeviceTreeUpdateHeader hdr = { .version_id = 1 }; > + CPUState *cs; > + int smt = kvmppc_smt_threads(); > > size -= sizeof(hdr); > > fdt = g_malloc0(size); > _FDT((fdt_create(fdt, size))); > + _FDT((fdt_begin_node(fdt, "cpus"))); > + > + CPU_FOREACH(cs) { > + PowerPCCPU *cpu = POWERPC_CPU(cs); > + DeviceClass *dc = DEVICE_GET_CLASS(cpu); > + int smpt = spapr_get_compat_smp_threads(cpu); > + int i, index = ppc_get_vcpu_dt_id(cpu); > + uint32_t servers_prop[smpt]; > + uint32_t gservers_prop[smpt * 2]; > + char tmp[32]; > + > + if ((index % smt) != 0) { > + continue; > + } > + > + snprintf(tmp, 32, "%s@%x", dc->fw_name, index); > + trace_spapr_cas_add_subnode(tmp); > + > + _FDT((fdt_begin_node(fdt, tmp))); > + _FDT((fdt_property_cell(fdt, "cpu-version", cpu->cpu_version))); > + > + /* Build interrupt servers and gservers properties */ > + for (i = 0; i < smpt; i++) { > + servers_prop[i] = cpu_to_be32(index + i); > + /* Hack, direct the group queues back to cpu 0 */ > + gservers_prop[i*2] = cpu_to_be32(index + i); > + gservers_prop[i*2 + 1] = 0; > + } > + _FDT((fdt_property(fdt, "ibm,ppc-interrupt-server#s", > + servers_prop, sizeof(servers_prop)))); > + _FDT((fdt_property(fdt, "ibm,ppc-interrupt-gserver#s", > + gservers_prop, sizeof(gservers_prop)))); > + > + _FDT((fdt_end_node(fdt))); > + } > + > + _FDT((fdt_end_node(fdt))); Why is this so much code? Can we only replace full nodes? Then please extract the original CPU node creation into a function and just call it from the original generation and from here. If we can also replace single properties I'd say we only need to override cpu-version. > > _FDT((fdt_finish(fdt))); > > diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c > index 2f6aa5c..cb815c3 100644 > --- a/hw/ppc/spapr_hcall.c > +++ b/hw/ppc/spapr_hcall.c > @@ -3,6 +3,9 @@ > #include "helper_regs.h" > #include "hw/ppc/spapr.h" > #include "mmu-hash64.h" > +#include "cpu-models.h" > +#include "trace.h" > +#include "kvm_ppc.h" > > struct SPRSyncState { > CPUState *cs; > @@ -752,12 +755,92 @@ out: > return ret; > } > > +#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 target_ulong h_client_architecture_support(PowerPCCPU *cpu_, > sPAPREnvironment *spapr, > target_ulong opcode, > target_ulong *args) > { > target_ulong list = args[0]; > + PowerPCCPUClass *pcc_ = POWERPC_CPU_GET_CLASS(cpu_); > + CPUState *cs; > + CPUState *cs_ = CPU(cpu_); > + bool cpu_match = false; > + unsigned old_cpu_version = cpu_->cpu_version; > + unsigned compat_lvl = 0, cpu_version = 0; > + unsigned max_lvl = get_compat_level(cpu_->max_compat); > + > + /* Parse PVR list */ > + for ( ; ; ) { > + uint32_t pvr, pvr_mask; > + > + pvr_mask = ldl_phys(cs_->as, list); We access memory that the guest thinks gets accessed by real mode, so we need to mask it again. Just use the rtas helpers. > + list += 4; > + pvr = ldl_phys(cs_->as, 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; > + cpu_version = 0; > + } else if (pvr == cpu_->cpu_version) { > + cpu_match = true; > + cpu_version = cpu_->cpu_version; > + } else if (!cpu_match) { > + /* If it is a logical PVR, try to determine the highest level */ > + unsigned lvl = get_compat_level(pvr); > + if (lvl) { > + bool is205 = (pcc_->pcr_mask & POWERPC_ISA_COMPAT_2_05) && > + (lvl == get_compat_level(CPU_POWERPC_LOGICAL_2_05)); > + bool is206 = (pcc_->pcr_mask & POWERPC_ISA_COMPAT_2_06) && > + ((lvl == get_compat_level(CPU_POWERPC_LOGICAL_2_06)) || > + (lvl == get_compat_level(CPU_POWERPC_LOGICAL_2_06_PLUS))); > + > + if (is205 || is206) { > + if (!max_lvl) { > + /* User did not set the level, choose the highest */ > + if (compat_lvl <= lvl) { > + compat_lvl = lvl; > + cpu_version = pvr; > + } > + } else if (max_lvl >= lvl) { > + /* User chose the level, don't set higher than this */ > + compat_lvl = lvl; > + cpu_version = pvr; > + } > + } > + } > + } > + /* Terminator record */ > + if (~pvr_mask & pvr) { > + break; > + } > + } > + > + /* For the future use: here @list points to the first capability */ > + > + /* Parsing finished */ > + trace_spapr_cas_pvr(cpu_->cpu_version, cpu_match, > + cpu_version, pcc_->pcr_mask); > + > + /* Update CPUs */ > + if (old_cpu_version != cpu_version) { > + CPU_FOREACH(cs) { > + PowerPCCPU *cpu = POWERPC_CPU(cs); > + > + ppc_set_compat(cpu, cpu_version); Better make this a run_on call to ensure the vcpus get their new compat properties set. Alex > + } > + } > + > + if (!cpu_version) { > + return H_SUCCESS; > + } > > if (!list) { > return H_SUCCESS; > diff --git a/trace-events b/trace-events > index 03565dc..c2db909 100644 > --- a/trace-events > +++ b/trace-events > @@ -1182,6 +1182,11 @@ xics_ics_eoi(int nr) "ics_eoi: irq %#x" > # hw/ppc/spapr.c > 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" > +spapr_cas_add_subnode(const char *s) "%s" > + > +# 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