[PATCH v2 05/16] KVM: PPC: Book3S HV: XIVE: add a control to configure a source
David Gibson
david at gibson.dropbear.id.au
Mon Feb 25 13:21:31 AEDT 2019
On Fri, Feb 22, 2019 at 12:28:29PM +0100, Cédric Le Goater wrote:
> This control will be used by the H_INT_SET_SOURCE_CONFIG hcall from
> QEMU and also to restore the configuration of the source in the KVM
> device.
>
> The XIVE internal IRQ structure is extended with the value of the
> Effective Interrupt Source Number. The EISN is the interrupt number
> pushed in the event queue that the guest OS will use to dispatch
> events internally. Caching the EISN value in KVM ease the test when
> checking if a reconfiguration is indeed needed.
>
> Signed-off-by: Cédric Le Goater <clg at kaod.org>
Reviewed-by: David Gibson <david at gibson.dropbear.id.au>
> ---
> arch/powerpc/include/uapi/asm/kvm.h | 11 +++
> arch/powerpc/kvm/book3s_xive.h | 4 +
> arch/powerpc/kvm/book3s_xive.c | 5 +-
> arch/powerpc/kvm/book3s_xive_native.c | 97 ++++++++++++++++++++++
> Documentation/virtual/kvm/devices/xive.txt | 20 +++++
> 5 files changed, 135 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
> index a9ad99f2a11b..91899c7f9abd 100644
> --- a/arch/powerpc/include/uapi/asm/kvm.h
> +++ b/arch/powerpc/include/uapi/asm/kvm.h
> @@ -678,9 +678,20 @@ struct kvm_ppc_cpu_char {
> /* POWER9 XIVE Native Interrupt Controller */
> #define KVM_DEV_XIVE_GRP_CTRL 1
> #define KVM_DEV_XIVE_GRP_SOURCE 2 /* 64-bit source attributes */
> +#define KVM_DEV_XIVE_GRP_SOURCE_CONFIG 3 /* 64-bit source attributes */
>
> /* Layout of 64-bit XIVE source attribute values */
> #define KVM_XIVE_LEVEL_SENSITIVE (1ULL << 0)
> #define KVM_XIVE_LEVEL_ASSERTED (1ULL << 1)
>
> +/* Layout of 64-bit XIVE source configuration attribute values */
> +#define KVM_XIVE_SOURCE_PRIORITY_SHIFT 0
> +#define KVM_XIVE_SOURCE_PRIORITY_MASK 0x7
> +#define KVM_XIVE_SOURCE_SERVER_SHIFT 3
> +#define KVM_XIVE_SOURCE_SERVER_MASK 0xfffffff8ULL
> +#define KVM_XIVE_SOURCE_MASK_SHIFT 32
> +#define KVM_XIVE_SOURCE_MASK_MASK 0x100000000ULL
> +#define KVM_XIVE_SOURCE_EISN_SHIFT 33
> +#define KVM_XIVE_SOURCE_EISN_MASK 0xfffffffe00000000ULL
> +
> #endif /* __LINUX_KVM_POWERPC_H */
> diff --git a/arch/powerpc/kvm/book3s_xive.h b/arch/powerpc/kvm/book3s_xive.h
> index f22f2d46d0f0..ab3ac152980d 100644
> --- a/arch/powerpc/kvm/book3s_xive.h
> +++ b/arch/powerpc/kvm/book3s_xive.h
> @@ -61,6 +61,9 @@ struct kvmppc_xive_irq_state {
> bool saved_p;
> bool saved_q;
> u8 saved_scan_prio;
> +
> + /* Xive native */
> + u32 eisn; /* Guest Effective IRQ number */
> };
>
> /* Select the "right" interrupt (IPI vs. passthrough) */
> @@ -263,6 +266,7 @@ int kvmppc_xive_debug_show_queues(struct seq_file *m, struct kvm_vcpu *vcpu);
> struct kvmppc_xive_src_block *kvmppc_xive_create_src_block(
> struct kvmppc_xive *xive, int irq);
> void kvmppc_xive_free_sources(struct kvmppc_xive_src_block *sb);
> +int kvmppc_xive_select_target(struct kvm *kvm, u32 *server, u8 prio);
>
> #endif /* CONFIG_KVM_XICS */
> #endif /* _KVM_PPC_BOOK3S_XICS_H */
> diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
> index 6f950ecb3592..086da91d7c6e 100644
> --- a/arch/powerpc/kvm/book3s_xive.c
> +++ b/arch/powerpc/kvm/book3s_xive.c
> @@ -342,7 +342,7 @@ static int xive_try_pick_queue(struct kvm_vcpu *vcpu, u8 prio)
> return atomic_add_unless(&q->count, 1, max) ? 0 : -EBUSY;
> }
>
> -static int xive_select_target(struct kvm *kvm, u32 *server, u8 prio)
> +int kvmppc_xive_select_target(struct kvm *kvm, u32 *server, u8 prio)
> {
> struct kvm_vcpu *vcpu;
> int i, rc;
> @@ -535,7 +535,7 @@ static int xive_target_interrupt(struct kvm *kvm,
> * priority. The count for that new target will have
> * already been incremented.
> */
> - rc = xive_select_target(kvm, &server, prio);
> + rc = kvmppc_xive_select_target(kvm, &server, prio);
>
> /*
> * We failed to find a target ? Not much we can do
> @@ -1509,6 +1509,7 @@ struct kvmppc_xive_src_block *kvmppc_xive_create_src_block(
>
> for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
> sb->irq_state[i].number = (bid << KVMPPC_XICS_ICS_SHIFT) | i;
> + sb->irq_state[i].eisn = 0;
> sb->irq_state[i].guest_priority = MASKED;
> sb->irq_state[i].saved_priority = MASKED;
> sb->irq_state[i].act_priority = MASKED;
> diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
> index a9b2d2d9af99..cb5a5c6e05af 100644
> --- a/arch/powerpc/kvm/book3s_xive_native.c
> +++ b/arch/powerpc/kvm/book3s_xive_native.c
> @@ -248,6 +248,99 @@ static int kvmppc_xive_native_set_source(struct kvmppc_xive *xive, long irq,
> return 0;
> }
>
> +static int kvmppc_xive_native_update_source_config(struct kvmppc_xive *xive,
> + struct kvmppc_xive_src_block *sb,
> + struct kvmppc_xive_irq_state *state,
> + u32 server,
> + u8 priority,
> + u32 eisn)
> +{
> + struct kvm *kvm = xive->kvm;
> + u32 hw_num;
> + int rc = 0;
> +
> + /*
> + * TODO: Do we need to safely mask and unmask a source ? can
> + * we just let the guest handle the possible races ?
> + */
> + arch_spin_lock(&sb->lock);
> +
> + if (state->act_server == server && state->act_priority == priority &&
> + state->eisn == eisn)
> + goto unlock;
> +
> + pr_devel("new_act_prio=%d new_act_server=%d act_server=%d act_prio=%d\n",
> + priority, server, state->act_server, state->act_priority);
> +
> + kvmppc_xive_select_irq(state, &hw_num, NULL);
> +
> + if (priority != MASKED) {
> + rc = kvmppc_xive_select_target(kvm, &server, priority);
> + if (rc)
> + goto unlock;
> +
> + state->act_priority = priority;
> + state->act_server = server;
> + state->eisn = eisn;
> +
> + rc = xive_native_configure_irq(hw_num, xive->vp_base + server,
> + priority, eisn);
> + } else {
> + state->act_priority = MASKED;
> + state->act_server = 0;
> + state->eisn = 0;
> +
> + rc = xive_native_configure_irq(hw_num, 0, MASKED, 0);
> + }
> +
> +unlock:
> + arch_spin_unlock(&sb->lock);
> + return rc;
> +}
> +
> +static int kvmppc_xive_native_set_source_config(struct kvmppc_xive *xive,
> + long irq, u64 addr)
> +{
> + struct kvmppc_xive_src_block *sb;
> + struct kvmppc_xive_irq_state *state;
> + u64 __user *ubufp = (u64 __user *) addr;
> + u16 src;
> + u64 kvm_cfg;
> + u32 server;
> + u8 priority;
> + u32 eisn;
> +
> + sb = kvmppc_xive_find_source(xive, irq, &src);
> + if (!sb)
> + return -ENOENT;
> +
> + state = &sb->irq_state[src];
> +
> + if (!state->valid)
> + return -EINVAL;
> +
> + if (get_user(kvm_cfg, ubufp))
> + return -EFAULT;
> +
> + pr_devel("%s irq=0x%lx cfg=%016llx\n", __func__, irq, kvm_cfg);
> +
> + priority = (kvm_cfg & KVM_XIVE_SOURCE_PRIORITY_MASK) >>
> + KVM_XIVE_SOURCE_PRIORITY_SHIFT;
> + server = (kvm_cfg & KVM_XIVE_SOURCE_SERVER_MASK) >>
> + KVM_XIVE_SOURCE_SERVER_SHIFT;
> + eisn = (kvm_cfg & KVM_XIVE_SOURCE_EISN_MASK) >>
> + KVM_XIVE_SOURCE_EISN_SHIFT;
> +
> + if (priority != xive_prio_from_guest(priority)) {
> + pr_err("invalid priority for queue %d for VCPU %d\n",
> + priority, server);
> + return -EINVAL;
> + }
> +
> + return kvmppc_xive_native_update_source_config(xive, sb, state, server,
> + priority, eisn);
> +}
> +
> static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
> struct kvm_device_attr *attr)
> {
> @@ -259,6 +352,9 @@ static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
> case KVM_DEV_XIVE_GRP_SOURCE:
> return kvmppc_xive_native_set_source(xive, attr->attr,
> attr->addr);
> + case KVM_DEV_XIVE_GRP_SOURCE_CONFIG:
> + return kvmppc_xive_native_set_source_config(xive, attr->attr,
> + attr->addr);
> }
> return -ENXIO;
> }
> @@ -276,6 +372,7 @@ static int kvmppc_xive_native_has_attr(struct kvm_device *dev,
> case KVM_DEV_XIVE_GRP_CTRL:
> break;
> case KVM_DEV_XIVE_GRP_SOURCE:
> + case KVM_DEV_XIVE_GRP_SOURCE_CONFIG:
> if (attr->attr >= KVMPPC_XIVE_FIRST_IRQ &&
> attr->attr < KVMPPC_XIVE_NR_IRQS)
> return 0;
> diff --git a/Documentation/virtual/kvm/devices/xive.txt b/Documentation/virtual/kvm/devices/xive.txt
> index cd8bfc37b72e..4f513a1880c7 100644
> --- a/Documentation/virtual/kvm/devices/xive.txt
> +++ b/Documentation/virtual/kvm/devices/xive.txt
> @@ -32,3 +32,23 @@ the legacy interrupt mode, referred as XICS (POWER7/8).
> -ENOMEM: Could not create a new source block
> -EFAULT: Invalid user pointer for attr->addr.
> -ENXIO: Could not allocate underlying HW interrupt
> +
> + 3. KVM_DEV_XIVE_GRP_SOURCE_CONFIG (write only)
> + Configures source targeting
> + Attributes:
> + Interrupt source number (64-bit)
> + The kvm_device_attr.addr points to a __u64 value:
> + bits: | 63 .... 33 | 32 | 31 .. 3 | 2 .. 0
> + values: | eisn | mask | server | priority
> + - priority: 0-7 interrupt priority level
> + - server: CPU number chosen to handle the interrupt
> + - mask: mask flag (unused)
> + - eisn: Effective Interrupt Source Number
> + Errors:
> + -ENOENT: Unknown source number
> + -EINVAL: Not initialized source number, invalid priority or
> + invalid CPU number.
> + -EFAULT: Invalid user pointer for attr->addr.
> + -ENXIO: CPU event queues not configured or configuration of the
> + underlying HW interrupt failed
> + -EBUSY: No CPU available to serve interrupt
--
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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