From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48191) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eYq65-0006RW-Ay for qemu-devel@nongnu.org; Tue, 09 Jan 2018 04:21:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eYq64-0001L4-73 for qemu-devel@nongnu.org; Tue, 09 Jan 2018 04:21:29 -0500 From: Suraj Jitindar Singh Date: Tue, 9 Jan 2018 20:21:03 +1100 Message-Id: <20180109092103.18458-4-sjitindarsingh@gmail.com> In-Reply-To: <20180109092103.18458-1-sjitindarsingh@gmail.com> References: <20180109092103.18458-1-sjitindarsingh@gmail.com> Subject: [Qemu-devel] [QEMU-PPC] [RFC 3/3] target/ppc: Add H-Call H_GET_CPU_CHARACTERISTICS List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-ppc@nongnu.org Cc: qemu-devel@nongnu.org, david@gibson.dropbear.id.au, paulus@ozlabs.org, Suraj Jitindar Singh The new H-Call H_GET_CPU_CHARACTERISTICS is used by the guest to query behaviours and available characteristics of the cpu. Implement the handler for this new H-Call which formulates its response based on the setting of the new capabilities added in the previous patch. Note: Currently we return H_FUNCTION under TCG which will direct the guest to fall back to doing a displacement flush Discussion: Is TCG affected? Is there any point in telling the guest to do these workarounds on TCG given they're unlikely to translate to host instructions which have the desired effect? --- hw/ppc/spapr_hcall.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++ include/hw/ppc/spapr.h | 1 + 2 files changed, 82 insertions(+) diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c index 51eba52e86..b62b47c8d9 100644 --- a/hw/ppc/spapr_hcall.c +++ b/hw/ppc/spapr_hcall.c @@ -1654,6 +1654,84 @@ static target_ulong h_client_architecture_support(PowerPCCPU *cpu, return H_SUCCESS; } +#define CPU_CHARACTERISTIC_SPEC_BARRIER (1ULL << (63 - 0)) +#define CPU_CHARACTERISTIC_BCCTR_SERIAL (1ULL << (63 - 1)) +#define CPU_CHARACTERISTIC_ORI_L1_CACHE (1ULL << (63 - 2)) +#define CPU_CHARACTERISTIC_MTTRIG_L1_CACHE (1ULL << (63 - 3)) +#define CPU_CHARACTERISTIC_L1_CACHE_PRIV (1ULL << (63 - 4)) +#define CPU_CHARACTERISTIC_BRANCH_HINTS (1ULL << (63 - 5)) +#define CPU_CHARACTERISTIC_MTTRIG_THR_RECONF (1ULL << (63 - 6)) +#define CPU_BEHAVIOUR_FAVOUR_SECURITY (1ULL << (63 - 0)) +#define CPU_BEHAVIOUR_L1_CACHE_FLUSH (1ULL << (63 - 1)) +#define CPU_BEHAVIOUR_SPEC_BARRIER (1ULL << (63 - 2)) + +static target_ulong h_get_cpu_characteristics(PowerPCCPU *cpu, + sPAPRMachineState *spapr, + target_ulong opcode, + target_ulong *args) +{ + uint64_t characteristics = CPU_CHARACTERISTIC_BRANCH_HINTS; + uint64_t behaviour = CPU_BEHAVIOUR_FAVOUR_SECURITY; + uint8_t safe_cache = spapr_get_cap(spapr, SPAPR_CAP_CFPC); + uint8_t safe_bounds_check = spapr_get_cap(spapr, SPAPR_CAP_SBBC); + uint8_t safe_indirect_branch = spapr_get_cap(spapr, SPAPR_CAP_IBS); + + /* TODO: Is TCG vulnerable? */ + if (!kvm_enabled()) { + return H_FUNCTION; + } + + switch (safe_cache) { + case SPAPR_CAP_WORKAROUND: + characteristics |= CPU_CHARACTERISTIC_ORI_L1_CACHE; + characteristics |= CPU_CHARACTERISTIC_MTTRIG_L1_CACHE; + characteristics |= CPU_CHARACTERISTIC_L1_CACHE_PRIV; + behaviour |= CPU_BEHAVIOUR_L1_CACHE_FLUSH; + break; + case SPAPR_CAP_FIXED: + break; + default: /* broken */ + if (safe_cache != SPAPR_CAP_BROKEN) { + error_report("Invalid value for KVM_CAP_PPC_SAFE_CACHE (%d), assuming broken", + safe_cache); + } + behaviour |= CPU_BEHAVIOUR_L1_CACHE_FLUSH; + break; + } + + switch (safe_bounds_check) { + case SPAPR_CAP_WORKAROUND: + characteristics |= CPU_CHARACTERISTIC_SPEC_BARRIER; + behaviour |= CPU_BEHAVIOUR_SPEC_BARRIER; + break; + case SPAPR_CAP_FIXED: + break; + default: /* broken */ + if (safe_bounds_check != SPAPR_CAP_BROKEN) { + error_report("Invalid value for KVM_CAP_PPC_SAFE_BOUNDS_CHECK (%d), assuming broken", + safe_bounds_check); + } + behaviour |= CPU_BEHAVIOUR_SPEC_BARRIER; + break; + } + + switch (safe_indirect_branch) { + case SPAPR_CAP_FIXED: + characteristics |= CPU_CHARACTERISTIC_BCCTR_SERIAL; + default: /* broken */ + if (safe_indirect_branch != SPAPR_CAP_BROKEN) { + error_report("Invalid value for KVM_CAP_PPC_SAFE_INDIRECT_BRANCH (%d), assuming broken", + safe_indirect_branch); + } + break; + } + + args[0] = characteristics; + args[1] = behaviour; + + return H_SUCCESS; +} + static spapr_hcall_fn papr_hypercall_table[(MAX_HCALL_OPCODE / 4) + 1]; static spapr_hcall_fn kvmppc_hypercall_table[KVMPPC_HCALL_MAX - KVMPPC_HCALL_BASE + 1]; @@ -1733,6 +1811,9 @@ static void hypercall_register_types(void) spapr_register_hypercall(H_INVALIDATE_PID, h_invalidate_pid); spapr_register_hypercall(H_REGISTER_PROC_TBL, h_register_process_table); + /* hcall-get-cpu-characteristics */ + spapr_register_hypercall(H_GET_CPU_CHARACTERISTICS, h_get_cpu_characteristics); + /* "debugger" hcalls (also used by SLOF). Note: We do -not- differenciate * here between the "CI" and the "CACHE" variants, they will use whatever * mapping attributes qemu is using. When using KVM, the kernel will diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h index 2db2f3e2e2..5677c38d2a 100644 --- a/include/hw/ppc/spapr.h +++ b/include/hw/ppc/spapr.h @@ -396,6 +396,7 @@ struct sPAPRMachineState { #define H_GET_HCA_INFO 0x1B8 #define H_GET_PERF_COUNT 0x1BC #define H_MANAGE_TRACE 0x1C0 +#define H_GET_CPU_CHARACTERISTICS 0x1C8 #define H_FREE_LOGICAL_LAN_BUFFER 0x1D4 #define H_QUERY_INT_STATE 0x1E4 #define H_POLL_PENDING 0x1D8 -- 2.13.6