On 30/10/16 22:11, David Gibson wrote:
> The pseries machine type is a bit unusual in that it runs a paravirtualized
> guest. The guest expects to interact with a hypervisor, and qemu
> emulates the functions of that hypervisor directly, rather than executing
> hypervisor code within the emulated system.
>
> To implement this in TCG, we need to intercept hypercall instructions and
> direct them to the machine's hypercall handlers, rather than attempting to
> perform a privilege change within TCG. This is controlled by a global
> hook - cpu_ppc_hypercall.
>
> This cleanup makes the handling a little cleaner and more extensible that
> a single global variable. Instead, each CPU to have hypercalls intercepted
> has a pointer set to a QOM object implementing a new virtual hypervisor
> interface. A method in that interface is called by TCG when it sees a
> hypercall instruction. It's possible we may want to add other methods in
> future.
Reviewed-by: Alexey Kardashevskiy <a...@ozlabs.ru>
I did not realize it is a global hook :)
>
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> hw/ppc/spapr.c | 8 +++++---
> hw/ppc/spapr_cpu_core.c | 1 +
> target-ppc/cpu.h | 26 ++++++++++++++++++++++++--
> target-ppc/excp_helper.c | 11 ++++-------
> target-ppc/translate_init.c | 12 ++++++++++++
> 5 files changed, 46 insertions(+), 12 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 3551439..b7762ee 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1006,7 +1006,8 @@ static uint64_t translate_kernel_address(void *opaque,
> uint64_t addr)
> return (addr & 0x0fffffff) + KERNEL_LOAD_ADDR;
> }
>
> -static void emulate_spapr_hypercall(PowerPCCPU *cpu)
> +static void emulate_spapr_hypercall(PPCVirtualHypervisor *vhyp,
> + PowerPCCPU *cpu)
> {
> CPUPPCState *env = &cpu->env;
>
> @@ -1778,8 +1779,6 @@ static void ppc_spapr_init(MachineState *machine)
>
> QLIST_INIT(&spapr->phbs);
>
> - cpu_ppc_hypercall = emulate_spapr_hypercall;
> -
> /* Allocate RMA if necessary */
> rma_alloc_size = kvmppc_alloc_rma(&rma);
>
> @@ -2610,6 +2609,7 @@ static void spapr_machine_class_init(ObjectClass *oc,
> void *data)
> FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(oc);
> NMIClass *nc = NMI_CLASS(oc);
> HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
> + PPCVirtualHypervisorClass *vhc = PPC_VIRTUAL_HYPERVISOR_CLASS(oc);
>
> mc->desc = "pSeries Logical Partition (PAPR compliant)";
>
> @@ -2641,6 +2641,7 @@ static void spapr_machine_class_init(ObjectClass *oc,
> void *data)
> fwc->get_dev_path = spapr_get_fw_dev_path;
> nc->nmi_monitor_handler = spapr_nmi;
> smc->phb_placement = spapr_phb_placement;
> + vhc->hypercall = emulate_spapr_hypercall;
> }
>
> static const TypeInfo spapr_machine_info = {
> @@ -2656,6 +2657,7 @@ static const TypeInfo spapr_machine_info = {
> { TYPE_FW_PATH_PROVIDER },
> { TYPE_NMI },
> { TYPE_HOTPLUG_HANDLER },
> + { TYPE_PPC_VIRTUAL_HYPERVISOR },
> { }
> },
> };
> diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
> index 1357293..ee5cd14 100644
> --- a/hw/ppc/spapr_cpu_core.c
> +++ b/hw/ppc/spapr_cpu_core.c
> @@ -57,6 +57,7 @@ static void spapr_cpu_init(sPAPRMachineState *spapr,
> PowerPCCPU *cpu,
> cpu_ppc_tb_init(env, SPAPR_TIMEBASE_FREQ);
>
> /* Enable PAPR mode in TCG or KVM */
> + cpu_ppc_set_vhyp(cpu, PPC_VIRTUAL_HYPERVISOR(spapr));
> cpu_ppc_set_papr(cpu);
>
> if (cpu->max_compat) {
> diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
> index 1c90adb..a655105 100644
> --- a/target-ppc/cpu.h
> +++ b/target-ppc/cpu.h
> @@ -1148,6 +1148,9 @@ do { \
> env->wdt_period[3] = (d_); \
> } while (0)
>
> +typedef struct PPCVirtualHypervisor PPCVirtualHypervisor;
> +typedef struct PPCVirtualHypervisorClass PPCVirtualHypervisorClass;
> +
> /**
> * PowerPCCPU:
> * @env: #CPUPPCState
> @@ -1166,6 +1169,7 @@ struct PowerPCCPU {
> int cpu_dt_id;
> uint32_t max_compat;
> uint32_t cpu_version;
> + PPCVirtualHypervisor *vhyp;
> };
>
> static inline PowerPCCPU *ppc_env_get_cpu(CPUPPCState *env)
> @@ -1180,6 +1184,25 @@ static inline PowerPCCPU *ppc_env_get_cpu(CPUPPCState
> *env)
> PowerPCCPUClass *ppc_cpu_class_by_pvr(uint32_t pvr);
> PowerPCCPUClass *ppc_cpu_class_by_pvr_mask(uint32_t pvr);
>
> +struct PPCVirtualHypervisor {
> + Object parent;
> +};
> +
> +struct PPCVirtualHypervisorClass {
> + InterfaceClass parent;
> + void (*hypercall)(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu);
> +};
> +
> +#define TYPE_PPC_VIRTUAL_HYPERVISOR "ppc-virtual-hypervisor"
> +#define PPC_VIRTUAL_HYPERVISOR(obj) \
> + OBJECT_CHECK(PPCVirtualHypervisor, (obj), TYPE_PPC_VIRTUAL_HYPERVISOR)
> +#define PPC_VIRTUAL_HYPERVISOR_CLASS(klass) \
> + OBJECT_CLASS_CHECK(PPCVirtualHypervisorClass, (klass), \
> + TYPE_PPC_VIRTUAL_HYPERVISOR)
> +#define PPC_VIRTUAL_HYPERVISOR_GET_CLASS(obj) \
> + OBJECT_GET_CLASS(PPCVirtualHypervisorClass, (obj), \
> + TYPE_PPC_VIRTUAL_HYPERVISOR)
> +
> void ppc_cpu_do_interrupt(CPUState *cpu);
> bool ppc_cpu_exec_interrupt(CPUState *cpu, int int_req);
> void ppc_cpu_dump_state(CPUState *cpu, FILE *f, fprintf_function cpu_fprintf,
> @@ -1252,6 +1275,7 @@ void store_booke_tcr (CPUPPCState *env, target_ulong
> val);
> void store_booke_tsr (CPUPPCState *env, target_ulong val);
> void ppc_tlb_invalidate_all (CPUPPCState *env);
> void ppc_tlb_invalidate_one (CPUPPCState *env, target_ulong addr);
> +void cpu_ppc_set_vhyp(PowerPCCPU *cpu, PPCVirtualHypervisor *vhyp);
> void cpu_ppc_set_papr(PowerPCCPU *cpu);
> #endif
> #endif
> @@ -2421,8 +2445,6 @@ static inline bool lsw_reg_in_range(int start, int
> nregs, int rx)
> (start + nregs > 32 && (rx >= start || rx < start + nregs - 32));
> }
>
> -extern void (*cpu_ppc_hypercall)(PowerPCCPU *);
> -
> void dump_mmu(FILE *f, fprintf_function cpu_fprintf, CPUPPCState *env);
>
> /**
> diff --git a/target-ppc/excp_helper.c b/target-ppc/excp_helper.c
> index 808760b..a077939 100644
> --- a/target-ppc/excp_helper.c
> +++ b/target-ppc/excp_helper.c
> @@ -35,11 +35,6 @@
> #endif
>
>
> /*****************************************************************************/
> -/* PowerPC Hypercall emulation */
> -
> -void (*cpu_ppc_hypercall)(PowerPCCPU *);
> -
> -/*****************************************************************************/
> /* Exception processing */
> #if defined(CONFIG_USER_ONLY)
> void ppc_cpu_do_interrupt(CPUState *cs)
> @@ -318,8 +313,10 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int
> excp_model, int excp)
> env->nip += 4;
>
> /* "PAPR mode" built-in hypercall emulation */
> - if ((lev == 1) && cpu_ppc_hypercall) {
> - cpu_ppc_hypercall(cpu);
> + if ((lev == 1) && cpu->vhyp) {
> + PPCVirtualHypervisorClass *vhc =
> + PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
> + vhc->hypercall(cpu->vhyp, cpu);
> return;
> }
> if (lev == 1) {
> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
> index 208fa1e..21899a4 100644
> --- a/target-ppc/translate_init.c
> +++ b/target-ppc/translate_init.c
> @@ -8857,6 +8857,11 @@ POWERPC_FAMILY(POWER9)(ObjectClass *oc, void *data)
>
> #if !defined(CONFIG_USER_ONLY)
>
> +void cpu_ppc_set_vhyp(PowerPCCPU *cpu, PPCVirtualHypervisor *vhyp)
> +{
> + cpu->vhyp = vhyp;
> +}
> +
> void cpu_ppc_set_papr(PowerPCCPU *cpu)
> {
> CPUPPCState *env = &cpu->env;
> @@ -10587,9 +10592,16 @@ static const TypeInfo ppc_cpu_type_info = {
> .class_init = ppc_cpu_class_init,
> };
>
> +static const TypeInfo ppc_vhyp_type_info = {
> + .name = TYPE_PPC_VIRTUAL_HYPERVISOR,
> + .parent = TYPE_INTERFACE,
> + .class_size = sizeof(PPCVirtualHypervisorClass),
> +};
> +
> static void ppc_cpu_register_types(void)
> {
> type_register_static(&ppc_cpu_type_info);
> + type_register_static(&ppc_vhyp_type_info);
> }
>
> type_init(ppc_cpu_register_types)
>
--
Alexey
