Re: [Qemu-devel] [PATCH 01/12] target/ppc/spapr: Set LPCR:HR when using Radix mode

[David Gibson <david@gibson.dropbear.id.au>]

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On Fri, Feb 15, 2019 at 06:00:18PM +0100, Cédric Le Goater wrote:
> From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> 
> The HW relies on LPCR:HR along with the PATE to determine whether
> to use Radix or Hash mode. In fact it uses LPCR:HR more commonly
> than the PATE.
> 
> For us, it's also more efficient to do so, especially since unlike
> the HW we do not maintain a cache of the current PATE and HV PATE
> in a generic place.
> 
> Prepare the grounds for that by ensuring that LPCR:HR is set
> properly on SPAPR machines.
> 
> Another option would have been to use a callback to get the PATE
> but this gets messy when implementing bare metal support, it's
> much simpler (and faster) to use LPCR.
> 
> Since existing migration streams may not have it, fix it up in
> spapr_post_load() as well based on the pseudo-PATE entry that
> we keep.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> ---
>  include/hw/ppc/spapr.h  |  1 +
>  target/ppc/cpu.h        |  1 +
>  hw/ppc/spapr.c          | 41 +++++++++++++++++++++++++++++++++++-
>  hw/ppc/spapr_hcall.c    | 46 +++++++----------------------------------
>  hw/ppc/spapr_rtas.c     |  6 +++---
>  target/ppc/mmu-hash64.c |  2 +-
>  6 files changed, 54 insertions(+), 43 deletions(-)
> 
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index a947a0a0dc14..734fb54b2a2d 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -840,4 +840,5 @@ void spapr_check_pagesize(sPAPRMachineState *spapr, hwaddr pagesize,
>  #define SPAPR_OV5_XIVE_EXPLOIT  0x40
>  #define SPAPR_OV5_XIVE_BOTH     0x80 /* Only to advertise on the platform */
>  
> +void spapr_set_all_lpcrs(target_ulong value, target_ulong mask);
>  #endif /* HW_SPAPR_H */
> diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> index 2c22292e7f41..e7c9ca8f5f84 100644
> --- a/target/ppc/cpu.h
> +++ b/target/ppc/cpu.h
> @@ -385,6 +385,7 @@ struct ppc_slb_t {
>  #define LPCR_AIL          (3ull << LPCR_AIL_SHIFT)
>  #define LPCR_UPRT         PPC_BIT(41) /* Use Process Table */
>  #define LPCR_EVIRT        PPC_BIT(42) /* Enhanced Virtualisation */
> +#define LPCR_HR           PPC_BIT(43) /* Host Radix */
>  #define LPCR_ONL          PPC_BIT(45)
>  #define LPCR_LD           PPC_BIT(46) /* Large Decrementer */
>  #define LPCR_P7_PECE0     PPC_BIT(49)
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 332cba89d425..60572eb59275 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1372,6 +1372,37 @@ static void emulate_spapr_hypercall(PPCVirtualHypervisor *vhyp,
>      }
>  }
>  
> +struct LPCRSyncState {
> +    target_ulong value;
> +    target_ulong mask;
> +};
> +
> +static void do_lpcr_sync(CPUState *cs, run_on_cpu_data arg)
> +{
> +    struct LPCRSyncState *s = arg.host_ptr;
> +    PowerPCCPU *cpu = POWERPC_CPU(cs);
> +    CPUPPCState *env = &cpu->env;
> +    target_ulong lpcr;
> +
> +    cpu_synchronize_state(cs);
> +    lpcr = env->spr[SPR_LPCR];
> +    lpcr &= ~s->mask;
> +    lpcr |= s->value;
> +    ppc_store_lpcr(cpu, lpcr);
> +}
> +
> +void spapr_set_all_lpcrs(target_ulong value, target_ulong mask)
> +{
> +    CPUState *cs;
> +    struct LPCRSyncState s = {
> +        .value = value,
> +        .mask = mask
> +    };
> +    CPU_FOREACH(cs) {
> +        run_on_cpu(cs, do_lpcr_sync, RUN_ON_CPU_HOST_PTR(&s));
> +    }
> +}
> +
>  static uint64_t spapr_get_patbe(PPCVirtualHypervisor *vhyp)
>  {
>      sPAPRMachineState *spapr = SPAPR_MACHINE(vhyp);
> @@ -1548,7 +1579,7 @@ void spapr_reallocate_hpt(sPAPRMachineState *spapr, int shift,
>          }
>      }
>      /* We're setting up a hash table, so that means we're not radix */
> -    spapr->patb_entry = 0;
> +    spapr_set_all_lpcrs(0, LPCR_HR | LPCR_UPRT);

I think we should still set the patb_entry as well as the LPCR here.
It might not matter, but it will be less confusing for debugging at
the least.  Apart from that nit,

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

>  }
>  
>  void spapr_setup_hpt_and_vrma(sPAPRMachineState *spapr)
> @@ -1606,6 +1637,7 @@ static void spapr_machine_reset(void)
>           * without a HPT because KVM will start them in radix mode.
>           * Set the GR bit in PATB so that we know there is no HPT. */
>          spapr->patb_entry = PATBE1_GR;
> +        spapr_set_all_lpcrs(LPCR_HR | LPCR_UPRT, LPCR_HR | LPCR_UPRT);
>      } else {
>          spapr_setup_hpt_and_vrma(spapr);
>      }
> @@ -1764,6 +1796,13 @@ static int spapr_post_load(void *opaque, int version_id)
>          bool radix = !!(spapr->patb_entry & PATBE1_GR);
>          bool gtse = !!(cpu->env.spr[SPR_LPCR] & LPCR_GTSE);
>  
> +        /*
> +         * Update LPCR:HR and UPRT as they may not be set properly in
> +         * the stream
> +         */
> +        spapr_set_all_lpcrs(radix ? (LPCR_HR | LPCR_UPRT) : 0,
> +                            LPCR_HR | LPCR_UPRT);
> +
>          err = kvmppc_configure_v3_mmu(cpu, radix, gtse, spapr->patb_entry);
>          if (err) {
>              error_report("Process table config unsupported by the host");
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 17bcaa3822c3..b47241ace62a 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -17,37 +17,6 @@
>  #include "mmu-book3s-v3.h"
>  #include "hw/mem/memory-device.h"
>  
> -struct LPCRSyncState {
> -    target_ulong value;
> -    target_ulong mask;
> -};
> -
> -static void do_lpcr_sync(CPUState *cs, run_on_cpu_data arg)
> -{
> -    struct LPCRSyncState *s = arg.host_ptr;
> -    PowerPCCPU *cpu = POWERPC_CPU(cs);
> -    CPUPPCState *env = &cpu->env;
> -    target_ulong lpcr;
> -
> -    cpu_synchronize_state(cs);
> -    lpcr = env->spr[SPR_LPCR];
> -    lpcr &= ~s->mask;
> -    lpcr |= s->value;
> -    ppc_store_lpcr(cpu, lpcr);
> -}
> -
> -static void set_all_lpcrs(target_ulong value, target_ulong mask)
> -{
> -    CPUState *cs;
> -    struct LPCRSyncState s = {
> -        .value = value,
> -        .mask = mask
> -    };
> -    CPU_FOREACH(cs) {
> -        run_on_cpu(cs, do_lpcr_sync, RUN_ON_CPU_HOST_PTR(&s));
> -    }
> -}
> -
>  static bool has_spr(PowerPCCPU *cpu, int spr)
>  {
>      /* We can test whether the SPR is defined by checking for a valid name */
> @@ -1255,12 +1224,12 @@ static target_ulong h_set_mode_resource_le(PowerPCCPU *cpu,
>  
>      switch (mflags) {
>      case H_SET_MODE_ENDIAN_BIG:
> -        set_all_lpcrs(0, LPCR_ILE);
> +        spapr_set_all_lpcrs(0, LPCR_ILE);
>          spapr_pci_switch_vga(true);
>          return H_SUCCESS;
>  
>      case H_SET_MODE_ENDIAN_LITTLE:
> -        set_all_lpcrs(LPCR_ILE, LPCR_ILE);
> +        spapr_set_all_lpcrs(LPCR_ILE, LPCR_ILE);
>          spapr_pci_switch_vga(false);
>          return H_SUCCESS;
>      }
> @@ -1289,7 +1258,7 @@ static target_ulong h_set_mode_resource_addr_trans_mode(PowerPCCPU *cpu,
>          return H_UNSUPPORTED_FLAG;
>      }
>  
> -    set_all_lpcrs(mflags << LPCR_AIL_SHIFT, LPCR_AIL);
> +    spapr_set_all_lpcrs(mflags << LPCR_AIL_SHIFT, LPCR_AIL);
>  
>      return H_SUCCESS;
>  }
> @@ -1422,10 +1391,11 @@ static target_ulong h_register_process_table(PowerPCCPU *cpu,
>  
>      spapr->patb_entry = cproc; /* Save new process table */
>  
> -    /* Update the UPRT and GTSE bits in the LPCR for all cpus */
> -    set_all_lpcrs(((flags & (FLAG_RADIX | FLAG_HASH_PROC_TBL)) ? LPCR_UPRT : 0) |
> -                  ((flags & FLAG_GTSE) ? LPCR_GTSE : 0),
> -                  LPCR_UPRT | LPCR_GTSE);
> +    /* Update the UPRT, HR and GTSE bits in the LPCR for all cpus */
> +    spapr_set_all_lpcrs(((flags & (FLAG_RADIX | FLAG_HASH_PROC_TBL)) ?
> +                         (LPCR_UPRT | LPCR_HR) : 0) |
> +                        ((flags & FLAG_GTSE) ? LPCR_GTSE : 0),
> +                        LPCR_UPRT | LPCR_HR | LPCR_GTSE);
>  
>      if (kvm_enabled()) {
>          return kvmppc_configure_v3_mmu(cpu, flags & FLAG_RADIX,
> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> index d6a0952154ac..7a2cb786a36a 100644
> --- a/hw/ppc/spapr_rtas.c
> +++ b/hw/ppc/spapr_rtas.c
> @@ -172,10 +172,10 @@ static void rtas_start_cpu(PowerPCCPU *callcpu, sPAPRMachineState *spapr,
>           * New cpus are expected to start in the same radix/hash mode
>           * as the existing CPUs
>           */
> -        if (ppc64_radix_guest(callcpu)) {
> -            lpcr |= LPCR_UPRT | LPCR_GTSE;
> +        if (ppc64_v3_radix(callcpu)) {
> +            lpcr |= LPCR_UPRT | LPCR_GTSE | LPCR_HR;
>          } else {
> -            lpcr &= ~(LPCR_UPRT | LPCR_GTSE);
> +            lpcr &= ~(LPCR_UPRT | LPCR_GTSE | LPCR_HR);
>          }
>      }
>      ppc_store_lpcr(newcpu, lpcr);
> diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
> index 276d9015e7c4..f1c7729332e6 100644
> --- a/target/ppc/mmu-hash64.c
> +++ b/target/ppc/mmu-hash64.c
> @@ -1084,7 +1084,7 @@ void ppc_store_lpcr(PowerPCCPU *cpu, target_ulong val)
>      case POWERPC_MMU_3_00: /* P9 */
>          lpcr = val & (LPCR_VPM1 | LPCR_ISL | LPCR_KBV | LPCR_DPFD |
>                        (LPCR_PECE_U_MASK & LPCR_HVEE) | LPCR_ILE | LPCR_AIL |
> -                      LPCR_UPRT | LPCR_EVIRT | LPCR_ONL |
> +                      LPCR_UPRT | LPCR_EVIRT | LPCR_ONL | LPCR_HR |
>                        (LPCR_PECE_L_MASK & (LPCR_PDEE | LPCR_HDEE | LPCR_EEE |
>                        LPCR_DEE | LPCR_OEE)) | LPCR_MER | LPCR_GTSE | LPCR_TC |
>                        LPCR_HEIC | LPCR_LPES0 | LPCR_HVICE | LPCR_HDICE);

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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