From: David Gibson <david@gibson.dropbear.id.au>
To: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, paulus@ozlabs.org
Subject: Re: [Qemu-devel] [QEMU-PPC] [RFC 2/3] hw/spapr/spapr_caps: Add new caps safe_[cache/bounds_check/indirect_branch]
Date: Wed, 10 Jan 2018 15:54:27 +1100 [thread overview]
Message-ID: <20180110045426.GA19773@umbus.fritz.box> (raw)
In-Reply-To: <20180109092103.18458-3-sjitindarsingh@gmail.com>
[-- Attachment #1: Type: text/plain, Size: 16682 bytes --]
On Tue, Jan 09, 2018 at 08:21:02PM +1100, Suraj Jitindar Singh wrote:
> This patch adds three new capabilities:
> cap-cfpc -> safe_cache
> cap-sbbc -> safe_bounds_check
> cap-ibs -> safe_indirect_branch
>
> Each capability is tristate with the possible values "broken",
> "workaround" or "fixed". Add generic getter and setter functions for
> this new capability type. Add these new capabilities to the capabilities
> list. The maximum value for the capabilities is queried from kvm through
> new kvm capabilities. The requested values are considered to be
> compatible if kvm can support an equal or higher value for each
> capability.
>
> Discussion:
> Currently these new capabilities default to broken to allow for
> backwards compatibility, is this the best option?
> ---
> hw/ppc/spapr.c | 6 ++
> hw/ppc/spapr_caps.c | 224 ++++++++++++++++++++++++++++++++++++++++++++++
> include/hw/ppc/spapr.h | 15 +++-
> linux-headers/linux/kvm.h | 3 +
> target/ppc/kvm.c | 28 ++++++
> target/ppc/kvm_ppc.h | 18 ++++
> 6 files changed, 293 insertions(+), 1 deletion(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 7fa45729ba..d9700b0254 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1765,6 +1765,9 @@ static const VMStateDescription vmstate_spapr = {
> &vmstate_spapr_cap_htm,
> &vmstate_spapr_cap_vsx,
> &vmstate_spapr_cap_dfp,
> + &vmstate_spapr_cap_cfpc,
> + &vmstate_spapr_cap_sbbc,
> + &vmstate_spapr_cap_ibs,
> NULL
> }
> };
> @@ -3837,6 +3840,9 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
> smc->default_caps.caps[SPAPR_CAP_HTM] = SPAPR_CAP_OFF;
> smc->default_caps.caps[SPAPR_CAP_VSX] = SPAPR_CAP_ON;
> smc->default_caps.caps[SPAPR_CAP_DFP] = SPAPR_CAP_ON;
> + smc->default_caps.caps[SPAPR_CAP_CFPC] = SPAPR_CAP_BROKEN;
> + smc->default_caps.caps[SPAPR_CAP_SBBC] = SPAPR_CAP_BROKEN;
> + smc->default_caps.caps[SPAPR_CAP_IBS] = SPAPR_CAP_BROKEN;
> spapr_caps_add_properties(smc, &error_abort);
> }
>
> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
> index af40f2e469..e6910aa191 100644
> --- a/hw/ppc/spapr_caps.c
> +++ b/hw/ppc/spapr_caps.c
> @@ -75,6 +75,64 @@ static void spapr_cap_set_bool(Object *obj, Visitor *v, const char *name,
> SPAPR_CAP_CMD_LINE;
> }
>
> +static void spapr_cap_get_tristate(Object *obj, Visitor *v, const char *name,
> + void *opaque, Error **errp)
> +{
> + sPAPRCapabilityInfo *cap = opaque;
> + sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
> + char *val = NULL;
> + uint8_t value = spapr_get_cap(spapr, cap->index);
> +
> + switch (value) {
> + case SPAPR_CAP_BROKEN:
> + val = g_strdup("broken");
> + break;
> + case SPAPR_CAP_WORKAROUND:
> + val = g_strdup("workaround");
> + break;
> + case SPAPR_CAP_FIXED:
> + val = g_strdup("fixed");
> + break;
> + default:
> + break;
> + }
> +
> + visit_type_str(v, name, &val, errp);
> + g_free(val);
> +}
> +
> +static void spapr_cap_set_tristate(Object *obj, Visitor *v, const char *name,
> + void *opaque, Error **errp)
> +{
> + sPAPRCapabilityInfo *cap = opaque;
> + sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
> + char *val;
> + Error *local_err = NULL;
> + uint8_t value;
> +
> + visit_type_str(v, name, &val, &local_err);
> + if (local_err) {
> + error_propagate(errp, local_err);
> + return;
> + }
> +
> + if (!strcasecmp(val, "broken")) {
> + value = SPAPR_CAP_BROKEN;
> + } else if (!strcasecmp(val, "workaround")) {
> + value = SPAPR_CAP_WORKAROUND;
> + } else if (!strcasecmp(val, "fixed")) {
> + value = SPAPR_CAP_FIXED;
> + } else {
> + error_setg(errp, "Invalid capability mode \"%s\" for cap-%s", val,
> + cap->name);
> + goto out;
> + }
> +
> + spapr->cmd_line_caps.caps[cap->index] = value | SPAPR_CAP_CMD_LINE;
> +out:
> + g_free(val);
> +}
> +
> static void cap_htm_allow(sPAPRMachineState *spapr, uint8_t val, Error **errp)
> {
> if (!val) {
> @@ -122,6 +180,31 @@ static void cap_dfp_allow(sPAPRMachineState *spapr, uint8_t val, Error **errp)
> }
> }
>
> +static void cap_safe_cache_allow(sPAPRMachineState *spapr, uint8_t val,
> + Error **errp)
> +{
> + if (kvm_enabled() && (val > kvmppc_get_cap_safe_cache())) {
> + error_setg(errp, "Requested safe cache capability level not supported by kvm, try a different value for cap-cfpc");
> + }
Maybe throw in a FIXME comment for TCG. Given the bugs can be
triggered via Javascript, there's a good chance they can be triggered
via TCG as well - but obviously we don't want to delay the KVM fixes
to work out what the TCG situation is.
> +}
> +
> +static void cap_safe_bounds_check_allow(sPAPRMachineState *spapr, uint8_t val,
> + Error **errp)
> +{
> + if (kvm_enabled() && (val > kvmppc_get_cap_safe_bounds_check())) {
> + error_setg(errp, "Requested safe bounds check capability level not supported by kvm, try a different value for cap-sbbc");
> + }
> +}
> +
> +static void cap_safe_indirect_branch_allow(sPAPRMachineState *spapr,
> + uint8_t val, Error **errp)
> +{
> + if (kvm_enabled() && (val > kvmppc_get_cap_safe_indirect_branch())) {
> + error_setg(errp, "Requested safe indirect branch capability level not supported by kvm, try a different value for cap-ibs");
> + }
> +}
> +
> +#define VALUE_DESC_TRISTATE " (broken, workaround, fixed)"
>
> sPAPRCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
> [SPAPR_CAP_HTM] = {
> @@ -154,6 +237,36 @@ sPAPRCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
> .type = "bool",
> .allow = cap_dfp_allow,
> },
> + [SPAPR_CAP_CFPC] = {
> + .name = "cfpc",
> + .description = "Cache Flush on Privilege Change",
> + .options = VALUE_DESC_TRISTATE,
> + .index = SPAPR_CAP_CFPC,
> + .get = spapr_cap_get_tristate,
> + .set = spapr_cap_set_tristate,
> + .type = "string",
> + .allow = cap_safe_cache_allow,
> + },
> + [SPAPR_CAP_SBBC] = {
> + .name = "sbbc",
> + .description = "Speculation Barrier Bounds Checking",
> + .options = VALUE_DESC_TRISTATE,
> + .index = SPAPR_CAP_SBBC,
> + .get = spapr_cap_get_tristate,
> + .set = spapr_cap_set_tristate,
> + .type = "string",
> + .allow = cap_safe_bounds_check_allow,
> + },
> + [SPAPR_CAP_IBS] = {
> + .name = "ibs",
> + .description = "Indirect Branch Serialisation",
> + .options = VALUE_DESC_TRISTATE,
> + .index = SPAPR_CAP_IBS,
> + .get = spapr_cap_get_tristate,
> + .set = spapr_cap_set_tristate,
> + .type = "string",
> + .allow = cap_safe_indirect_branch_allow,
> + },
> };
>
> static sPAPRCapabilities default_caps_with_cpu(sPAPRMachineState *spapr,
> @@ -326,6 +439,117 @@ const VMStateDescription vmstate_spapr_cap_dfp = {
> },
> };
>
> +static bool spapr_cap_safe_cache_needed(void *opaque)
> +{
> + sPAPRMachineState *spapr = opaque;
> +
> + return !!(spapr->cmd_line_caps.caps[SPAPR_CAP_CFPC] & SPAPR_CAP_CMD_LINE);
> +}
> +
> +static int spapr_cap_safe_cache_pre_save(void *opaque)
> +{
> + sPAPRMachineState *spapr = opaque;
> +
> + spapr->mig_caps.caps[SPAPR_CAP_CFPC] =
> + spapr->cmd_line_caps.caps[SPAPR_CAP_CFPC];
> + return 0;
> +}
> +
> +static int spapr_cap_safe_cache_pre_load(void *opaque)
> +{
> + sPAPRMachineState *spapr = opaque;
> +
> + spapr->mig_caps.caps[SPAPR_CAP_CFPC] = 0;
> + return 0;
> +}
> +
> +const VMStateDescription vmstate_spapr_cap_cfpc = {
> + .name = "spapr/cap_cfpc",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .needed = spapr_cap_safe_cache_needed,
> + .pre_save = spapr_cap_safe_cache_pre_save,
> + .pre_load = spapr_cap_safe_cache_pre_load,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINT8(mig_caps.caps[SPAPR_CAP_CFPC], sPAPRMachineState),
> + VMSTATE_END_OF_LIST()
> + },
> +};
> +
> +static bool spapr_cap_safe_bounds_check_needed(void *opaque)
> +{
> + sPAPRMachineState *spapr = opaque;
> +
> + return !!(spapr->cmd_line_caps.caps[SPAPR_CAP_SBBC] & SPAPR_CAP_CMD_LINE);
> +}
> +
> +static int spapr_cap_safe_bounds_check_pre_save(void *opaque)
> +{
> + sPAPRMachineState *spapr = opaque;
> +
> + spapr->mig_caps.caps[SPAPR_CAP_SBBC] =
> + spapr->cmd_line_caps.caps[SPAPR_CAP_SBBC];
> + return 0;
> +}
> +
> +static int spapr_cap_safe_bounds_check_pre_load(void *opaque)
> +{
> + sPAPRMachineState *spapr = opaque;
> +
> + spapr->mig_caps.caps[SPAPR_CAP_SBBC] = 0;
> + return 0;
> +}
> +
> +const VMStateDescription vmstate_spapr_cap_sbbc = {
> + .name = "spapr/cap_sbbc",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .needed = spapr_cap_safe_bounds_check_needed,
> + .pre_save = spapr_cap_safe_bounds_check_pre_save,
> + .pre_load = spapr_cap_safe_bounds_check_pre_load,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINT8(mig_caps.caps[SPAPR_CAP_SBBC], sPAPRMachineState),
> + VMSTATE_END_OF_LIST()
> + },
> +};
> +
> +static bool spapr_cap_safe_indirect_branch_needed(void *opaque)
> +{
> + sPAPRMachineState *spapr = opaque;
> +
> + return !!(spapr->cmd_line_caps.caps[SPAPR_CAP_IBS] & SPAPR_CAP_CMD_LINE);
> +}
> +
> +static int spapr_cap_safe_indirect_branch_pre_save(void *opaque)
> +{
> + sPAPRMachineState *spapr = opaque;
> +
> + spapr->mig_caps.caps[SPAPR_CAP_IBS] =
> + spapr->cmd_line_caps.caps[SPAPR_CAP_IBS];
> + return 0;
> +}
> +
> +static int spapr_cap_safe_indirect_branch_pre_load(void *opaque)
> +{
> + sPAPRMachineState *spapr = opaque;
> +
> + spapr->mig_caps.caps[SPAPR_CAP_IBS] = 0;
> + return 0;
> +}
> +
> +const VMStateDescription vmstate_spapr_cap_ibs = {
> + .name = "spapr/cap_ibs",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .needed = spapr_cap_safe_indirect_branch_needed,
> + .pre_save = spapr_cap_safe_indirect_branch_pre_save,
> + .pre_load = spapr_cap_safe_indirect_branch_pre_load,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINT8(mig_caps.caps[SPAPR_CAP_IBS], sPAPRMachineState),
> + VMSTATE_END_OF_LIST()
> + },
> +};
> +
> void spapr_caps_reset(sPAPRMachineState *spapr)
> {
> sPAPRCapabilities caps;
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 2804fbbf12..2db2f3e2e2 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -62,8 +62,14 @@ typedef enum {
> #define SPAPR_CAP_VSX 0x01
> /* Decimal Floating Point */
> #define SPAPR_CAP_DFP 0x02
> +/* Cache Flush on Privilege Change */
> +#define SPAPR_CAP_CFPC 0x03
> +/* Speculation Barrier Bounds Checking */
> +#define SPAPR_CAP_SBBC 0x04
> +/* Indirect Branch Serialisation */
> +#define SPAPR_CAP_IBS 0x05
> /* Num Caps */
> -#define SPAPR_CAP_NUM (SPAPR_CAP_DFP + 1)
> +#define SPAPR_CAP_NUM (SPAPR_CAP_IBS + 1)
>
> /*
> * Capability Values
> @@ -73,6 +79,10 @@ typedef enum {
> /* Bool Caps */
> #define SPAPR_CAP_OFF 0x00
> #define SPAPR_CAP_ON 0x01
> +/* Broken | Workaround | Fixed Caps */
> +#define SPAPR_CAP_BROKEN 0x00
> +#define SPAPR_CAP_WORKAROUND 0x01
> +#define SPAPR_CAP_FIXED 0x02
>
> typedef struct sPAPRCapabilities sPAPRCapabilities;
> struct sPAPRCapabilities {
> @@ -763,6 +773,9 @@ qemu_irq spapr_qirq(sPAPRMachineState *spapr, int irq);
> extern const VMStateDescription vmstate_spapr_cap_htm;
> extern const VMStateDescription vmstate_spapr_cap_vsx;
> extern const VMStateDescription vmstate_spapr_cap_dfp;
> +extern const VMStateDescription vmstate_spapr_cap_cfpc;
> +extern const VMStateDescription vmstate_spapr_cap_sbbc;
> +extern const VMStateDescription vmstate_spapr_cap_ibs;
>
> static inline uint8_t spapr_get_cap(sPAPRMachineState *spapr, int cap)
> {
> diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
> index ce6c2f11f4..0abe0a0abb 100644
> --- a/linux-headers/linux/kvm.h
> +++ b/linux-headers/linux/kvm.h
> @@ -932,6 +932,9 @@ struct kvm_ppc_resize_hpt {
> #define KVM_CAP_HYPERV_SYNIC2 148
> #define KVM_CAP_HYPERV_VP_INDEX 149
> #define KVM_CAP_S390_AIS_MIGRATION 150
> +#define KVM_CAP_PPC_SAFE_CACHE 151
> +#define KVM_CAP_PPC_SAFE_BOUNDS_CHECK 152
> +#define KVM_CAP_PPC_SAFE_INDIRECT_BRANCH 153
>
> #ifdef KVM_CAP_IRQ_ROUTING
>
> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> index 518dd06e98..818499237c 100644
> --- a/target/ppc/kvm.c
> +++ b/target/ppc/kvm.c
> @@ -89,6 +89,9 @@ static int cap_mmu_radix;
> static int cap_mmu_hash_v3;
> static int cap_resize_hpt;
> static int cap_ppc_pvr_compat;
> +static int cap_ppc_safe_cache;
> +static int cap_ppc_safe_bounds_check;
> +static int cap_ppc_safe_indirect_branch;
>
> static uint32_t debug_inst_opcode;
>
> @@ -147,6 +150,16 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
> cap_mmu_radix = kvm_vm_check_extension(s, KVM_CAP_PPC_MMU_RADIX);
> cap_mmu_hash_v3 = kvm_vm_check_extension(s, KVM_CAP_PPC_MMU_HASH_V3);
> cap_resize_hpt = kvm_vm_check_extension(s, KVM_CAP_SPAPR_RESIZE_HPT);
> + cap_ppc_safe_cache = kvm_vm_check_extension(s, KVM_CAP_PPC_SAFE_CACHE);
> + cap_ppc_safe_cache = cap_ppc_safe_cache > 0 ? cap_ppc_safe_cache : 0;
> + cap_ppc_safe_bounds_check = kvm_vm_check_extension(s,
> + KVM_CAP_PPC_SAFE_BOUNDS_CHECK);
> + cap_ppc_safe_bounds_check = cap_ppc_safe_bounds_check > 0 ?
> + cap_ppc_safe_bounds_check : 0;
> + cap_ppc_safe_indirect_branch = kvm_vm_check_extension(s,
> + KVM_CAP_PPC_SAFE_INDIRECT_BRANCH);
> + cap_ppc_safe_indirect_branch = cap_ppc_safe_indirect_branch > 0 ?
> + cap_ppc_safe_indirect_branch : 0;
> /*
> * Note: setting it to false because there is not such capability
> * in KVM at this moment.
> @@ -2456,6 +2469,21 @@ bool kvmppc_has_cap_mmu_hash_v3(void)
> return cap_mmu_hash_v3;
> }
>
> +int kvmppc_get_cap_safe_cache(void)
> +{
> + return cap_ppc_safe_cache;
> +}
> +
> +int kvmppc_get_cap_safe_bounds_check(void)
> +{
> + return cap_ppc_safe_bounds_check;
> +}
> +
> +int kvmppc_get_cap_safe_indirect_branch(void)
> +{
> + return cap_ppc_safe_indirect_branch;
> +}
> +
> PowerPCCPUClass *kvm_ppc_get_host_cpu_class(void)
> {
> uint32_t host_pvr = mfpvr();
> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
> index ecb55493cc..39830baa77 100644
> --- a/target/ppc/kvm_ppc.h
> +++ b/target/ppc/kvm_ppc.h
> @@ -59,6 +59,9 @@ bool kvmppc_has_cap_fixup_hcalls(void);
> bool kvmppc_has_cap_htm(void);
> bool kvmppc_has_cap_mmu_radix(void);
> bool kvmppc_has_cap_mmu_hash_v3(void);
> +int kvmppc_get_cap_safe_cache(void);
> +int kvmppc_get_cap_safe_bounds_check(void);
> +int kvmppc_get_cap_safe_indirect_branch(void);
> int kvmppc_enable_hwrng(void);
> int kvmppc_put_books_sregs(PowerPCCPU *cpu);
> PowerPCCPUClass *kvm_ppc_get_host_cpu_class(void);
> @@ -290,6 +293,21 @@ static inline bool kvmppc_has_cap_mmu_hash_v3(void)
> return false;
> }
>
> +static inline int kvmppc_get_cap_safe_cache(void)
> +{
> + return 0;
> +}
> +
> +static inline int kvmppc_get_cap_safe_bounds_check(void)
> +{
> + return 0;
> +}
> +
> +static inline int kvmppc_get_cap_safe_indirect_branch(void)
> +{
> + return 0;
> +}
> +
> static inline int kvmppc_enable_hwrng(void)
> {
> return -1;
--
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
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next prev parent reply other threads:[~2018-01-10 5:02 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-09 9:21 [Qemu-devel] [QEMU-PPC] [RFC 0/3] target/ppc: Rework spapr_caps Suraj Jitindar Singh
2018-01-09 9:21 ` [Qemu-devel] [QEMU-PPC] [RFC 1/3] hw/ppc/spapr_caps: Rework spapr_caps to use uint8 internal representation Suraj Jitindar Singh
2018-01-09 11:13 ` [Qemu-devel] [Qemu-ppc] " Murilo Opsfelder Araújo
2018-01-10 0:21 ` Suraj Jitindar Singh
2018-01-09 12:07 ` Andrea Bolognani
2018-01-10 0:19 ` Suraj Jitindar Singh
2018-01-10 2:51 ` David Gibson
2018-01-10 4:13 ` [Qemu-devel] " David Gibson
2018-01-12 2:19 ` Suraj Jitindar Singh
2018-01-09 9:21 ` [Qemu-devel] [QEMU-PPC] [RFC 2/3] hw/spapr/spapr_caps: Add new caps safe_[cache/bounds_check/indirect_branch] Suraj Jitindar Singh
2018-01-09 11:15 ` [Qemu-devel] [Qemu-ppc] " Murilo Opsfelder Araújo
2018-01-10 0:25 ` Suraj Jitindar Singh
2018-01-09 12:02 ` [Qemu-devel] " joserz
2018-01-10 0:23 ` Suraj Jitindar Singh
2018-01-10 4:54 ` David Gibson [this message]
2018-01-09 9:21 ` [Qemu-devel] [QEMU-PPC] [RFC 3/3] target/ppc: Add H-Call H_GET_CPU_CHARACTERISTICS Suraj Jitindar Singh
2018-01-09 11:19 ` [Qemu-devel] [Qemu-ppc] " Murilo Opsfelder Araújo
2018-01-10 0:26 ` Suraj Jitindar Singh
2018-01-10 5:02 ` [Qemu-devel] " David Gibson
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