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Re: [PATCH v2 4/4] target/ppc: Add POWER10 exception model
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From: |
David Gibson |
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Subject: |
Re: [PATCH v2 4/4] target/ppc: Add POWER10 exception model |
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Date: |
Fri, 16 Apr 2021 14:28:57 +1000 |
On Thu, Apr 15, 2021 at 03:42:27PM +1000, Nicholas Piggin wrote:
> POWER10 adds a new bit that modifies interrupt behaviour, LPCR[HAIL],
> and it removes support for the LPCR[AIL]=0b10 mode.
>
> Reviewed-by: Cédric Le Goater <clg@kaod.org>
> Tested-by: Cédric Le Goater <clg@kaod.org>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
> hw/ppc/spapr_hcall.c | 7 ++++-
> target/ppc/cpu-qom.h | 2 ++
> target/ppc/cpu.h | 5 ++--
> target/ppc/excp_helper.c | 51 +++++++++++++++++++++++++++++++--
> target/ppc/translate.c | 3 +-
> target/ppc/translate_init.c.inc | 2 +-
> 6 files changed, 62 insertions(+), 8 deletions(-)
>
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 2fbe04a689..6802cd4dc8 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -1396,7 +1396,12 @@ static target_ulong
> h_set_mode_resource_addr_trans_mode(PowerPCCPU *cpu,
> }
>
> if (mflags == 1) {
> - /* AIL=1 is reserved */
> + /* AIL=1 is reserved in POWER8/POWER9 */
> + return H_UNSUPPORTED_FLAG;
> + }
> +
> + if (mflags == 2 && (pcc->insns_flags2 & PPC2_ISA310)) {
> + /* AIL=2 is also reserved in POWER10 (ISA v3.1) */
> return H_UNSUPPORTED_FLAG;
> }
>
> diff --git a/target/ppc/cpu-qom.h b/target/ppc/cpu-qom.h
> index 118baf8d41..06b6571bc9 100644
> --- a/target/ppc/cpu-qom.h
> +++ b/target/ppc/cpu-qom.h
> @@ -116,6 +116,8 @@ enum powerpc_excp_t {
> POWERPC_EXCP_POWER8,
> /* POWER9 exception model */
> POWERPC_EXCP_POWER9,
> + /* POWER10 exception model */
> + POWERPC_EXCP_POWER10,
> };
>
>
> /*****************************************************************************/
> diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> index 5200a16d23..9d35cdfa92 100644
> --- a/target/ppc/cpu.h
> +++ b/target/ppc/cpu.h
> @@ -354,10 +354,11 @@ typedef struct ppc_v3_pate_t {
> #define LPCR_PECE_U_SHIFT (63 - 19)
> #define LPCR_PECE_U_MASK (0x7ull << LPCR_PECE_U_SHIFT)
> #define LPCR_HVEE PPC_BIT(17) /* Hypervisor Virt Exit Enable */
> -#define LPCR_RMLS_SHIFT (63 - 37)
> +#define LPCR_RMLS_SHIFT (63 - 37) /* RMLS (removed in ISA v3.0) */
> #define LPCR_RMLS (0xfull << LPCR_RMLS_SHIFT)
> +#define LPCR_HAIL PPC_BIT(37) /* ISA v3.1 HV AIL=3 equivalent */
> #define LPCR_ILE PPC_BIT(38)
> -#define LPCR_AIL_SHIFT (63 - 40) /* Alternate interrupt location */
> +#define LPCR_AIL_SHIFT (63 - 40) /* Alternate interrupt location */
> #define LPCR_AIL (3ull << LPCR_AIL_SHIFT)
> #define LPCR_UPRT PPC_BIT(41) /* Use Process Table */
> #define LPCR_EVIRT PPC_BIT(42) /* Enhanced Virtualisation */
> diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
> index 964a58cfdc..38a1482519 100644
> --- a/target/ppc/excp_helper.c
> +++ b/target/ppc/excp_helper.c
> @@ -170,7 +170,27 @@ static int powerpc_reset_wakeup(CPUState *cs,
> CPUPPCState *env, int excp,
> * +-------------------------------------------------------+
> *
> * The difference with POWER9 being that MSR[HV] 0->1 interrupts can be sent
> to
> - * the hypervisor in AIL mode if the guest is radix.
> + * the hypervisor in AIL mode if the guest is radix. This is good for
> + * performance but allows the guest to influence the AIL of hypervisor
> + * interrupts using its MSR, and also the hypervisor must disallow guest
> + * interrupts (MSR[HV] 0->0) from using AIL if the hypervisor does not want
> to
> + * use AIL for its MSR[HV] 0->1 interrupts.
> + *
> + * POWER10 addresses those issues with a new LPCR[HAIL] bit that is applied
> to
> + * interrupts that begin execution with MSR[HV]=1 (so both MSR[HV] 0->1 and
> + * MSR[HV] 1->1).
> + *
> + * HAIL=1 is equivalent to AIL=3, for interrupts delivered with MSR[HV]=1.
> + *
> + * POWER10 behaviour is
> + * | LPCR[AIL] | LPCR[HAIL] | MSR[IR||DR] | MSR[HV] | new MSR[HV] | AIL |
> + * +-----------+------------+-------------+---------+-------------+-----+
> + * | a | h | 00/01/10 | 0 | 0 | 0 |
> + * | a | h | 11 | 0 | 0 | a |
> + * | a | h | x | 0 | 1 | h |
> + * | a | h | 00/01/10 | 1 | 1 | 0 |
> + * | a | h | 11 | 1 | 1 | h |
> + * +--------------------------------------------------------------------+
> */
> static inline void ppc_excp_apply_ail(PowerPCCPU *cpu, int excp_model, int
> excp,
> target_ulong msr,
> @@ -210,6 +230,29 @@ static inline void ppc_excp_apply_ail(PowerPCCPU *cpu,
> int excp_model, int excp,
> /* AIL=1 is reserved */
> return;
> }
> +
> + } else if (excp_model == POWERPC_EXCP_POWER10) {
> + if (!mmu_all_on && !hv_escalation) {
> + /*
> + * AIL works for HV interrupts even with guest MSR[IR/DR]
> disabled.
> + * Guest->guest and HV->HV interrupts do require MMU on.
> + */
> + return;
> + }
> +
> + if (*new_msr & MSR_HVB) {
> + if (!(env->spr[SPR_LPCR] & LPCR_HAIL)) {
> + /* HV interrupts depend on LPCR[HAIL] */
> + return;
> + }
> + ail = 3; /* HAIL=1 gives AIL=3 behaviour for HV interrupts */
> + } else {
> + ail = (env->spr[SPR_LPCR] & LPCR_AIL) >> LPCR_AIL_SHIFT;
> + }
> + if (ail != 3) {
> + /* AIL=1 and AIL=2 are reserved */
> + return;
As with POWER9, I wonder if we should actuall filter this at LPCR
write time and assert() here.
On actual hardware, what will happen if you attempt to write a bad AIL
to the LPCR?
> + }
> } else {
> /* Other processors do not support AIL */
> return;
> @@ -322,7 +365,8 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int
> excp_model, int excp)
> #if defined(TARGET_PPC64)
> if (excp_model == POWERPC_EXCP_POWER7 ||
> excp_model == POWERPC_EXCP_POWER8 ||
> - excp_model == POWERPC_EXCP_POWER9) {
> + excp_model == POWERPC_EXCP_POWER9 ||
> + excp_model == POWERPC_EXCP_POWER10) {
> lpes0 = !!(env->spr[SPR_LPCR] & LPCR_LPES0);
> } else
> #endif /* defined(TARGET_PPC64) */
> @@ -842,7 +886,8 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int
> excp_model, int excp)
> } else if (env->spr[SPR_LPCR] & LPCR_ILE) {
> new_msr |= (target_ulong)1 << MSR_LE;
> }
> - } else if (excp_model == POWERPC_EXCP_POWER9) {
> + } else if (excp_model == POWERPC_EXCP_POWER9 ||
> + excp_model == POWERPC_EXCP_POWER10) {
> if (new_msr & MSR_HVB) {
> if (env->spr[SPR_HID0] & HID0_POWER9_HILE) {
> new_msr |= (target_ulong)1 << MSR_LE;
> diff --git a/target/ppc/translate.c b/target/ppc/translate.c
> index 0984ce637b..e9ed001229 100644
> --- a/target/ppc/translate.c
> +++ b/target/ppc/translate.c
> @@ -7731,7 +7731,8 @@ void ppc_cpu_dump_state(CPUState *cs, FILE *f, int
> flags)
> #if defined(TARGET_PPC64)
> if (env->excp_model == POWERPC_EXCP_POWER7 ||
> env->excp_model == POWERPC_EXCP_POWER8 ||
> - env->excp_model == POWERPC_EXCP_POWER9) {
> + env->excp_model == POWERPC_EXCP_POWER9 ||
> + env->excp_model == POWERPC_EXCP_POWER10) {
> qemu_fprintf(f, "HSRR0 " TARGET_FMT_lx " HSRR1 " TARGET_FMT_lx "\n",
> env->spr[SPR_HSRR0], env->spr[SPR_HSRR1]);
> }
> diff --git a/target/ppc/translate_init.c.inc b/target/ppc/translate_init.c.inc
> index a82d9ed647..76d82cc2f6 100644
> --- a/target/ppc/translate_init.c.inc
> +++ b/target/ppc/translate_init.c.inc
> @@ -9317,7 +9317,7 @@ POWERPC_FAMILY(POWER10)(ObjectClass *oc, void *data)
> pcc->radix_page_info = &POWER10_radix_page_info;
> pcc->lrg_decr_bits = 56;
> #endif
> - pcc->excp_model = POWERPC_EXCP_POWER9;
> + pcc->excp_model = POWERPC_EXCP_POWER10;
> pcc->bus_model = PPC_FLAGS_INPUT_POWER9;
> pcc->bfd_mach = bfd_mach_ppc64;
> pcc->flags = POWERPC_FLAG_VRE | POWERPC_FLAG_SE |
--
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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- [PATCH v2 1/4] target/ppc: Fix POWER9 radix guest HV interrupt AIL behaviour, (continued)