On Wed, Mar 20, 2019 at 09:37:40AM +0100, Cédric Le Goater wrote:
> These controls will be used by the H_INT_SET_QUEUE_CONFIG and
> H_INT_GET_QUEUE_CONFIG hcalls from QEMU to configure the underlying
> Event Queue in the XIVE IC. They will also be used to restore the
> configuration of the XIVE EQs and to capture the internal run-time
> state of the EQs. Both 'get' and 'set' rely on an OPAL call to access
> the EQ toggle bit and EQ index which are updated by the XIVE IC when
> event notifications are enqueued in the EQ.
>
> The value of the guest physical address of the event queue is saved in
> the XIVE internal xive_q structure for later use. That is when
> migration needs to mark the EQ pages dirty to capture a consistent
> memory state of the VM.
>
> To be noted that H_INT_SET_QUEUE_CONFIG does not require the extra
> OPAL call setting the EQ toggle bit and EQ index to configure the EQ,
> but restoring the EQ state will.
>
> Signed-off-by: Cédric Le Goater <clg@xxxxxxxx>
> ---
>
> Changes since v3 :
>
> - fix the test ont the initial setting of the EQ toggle bit : 0 -> 1
> - renamed qsize to qshift
> - renamed qpage to qaddr
> - checked host page size
> - limited flags to KVM_XIVE_EQ_ALWAYS_NOTIFY to fit sPAPR specs
>
> Changes since v2 :
>
> - fixed comments on the KVM device attribute definitions
> - fixed check on supported EQ size to restrict to 64K pages
> - checked kvm_eq.flags that need to be zero
> - removed the OPAL call when EQ qtoggle bit and index are zero.
>
> arch/powerpc/include/asm/xive.h | 2 +
> arch/powerpc/include/uapi/asm/kvm.h | 19 ++
> arch/powerpc/kvm/book3s_xive.h | 2 +
> arch/powerpc/kvm/book3s_xive.c | 15 +-
> arch/powerpc/kvm/book3s_xive_native.c | 242 +++++++++++++++++++++
> Documentation/virtual/kvm/devices/xive.txt | 34 +++
> 6 files changed, 308 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/xive.h b/arch/powerpc/include/asm/xive.h
> index b579a943407b..c4e88abd3b67 100644
> --- a/arch/powerpc/include/asm/xive.h
> +++ b/arch/powerpc/include/asm/xive.h
> @@ -73,6 +73,8 @@ struct xive_q {
> u32 esc_irq;
> atomic_t count;
> atomic_t pending_count;
> + u64 guest_qaddr;
> + u32 guest_qshift;
> };
>
> /* Global enable flags for the XIVE support */
> diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
> index e8161e21629b..85005400fd86 100644
> --- a/arch/powerpc/include/uapi/asm/kvm.h
> +++ b/arch/powerpc/include/uapi/asm/kvm.h
> @@ -681,6 +681,7 @@ struct kvm_ppc_cpu_char {
> #define KVM_DEV_XIVE_GRP_CTRL 1
> #define KVM_DEV_XIVE_GRP_SOURCE 2 /* 64-bit source identifier */
> #define KVM_DEV_XIVE_GRP_SOURCE_CONFIG 3 /* 64-bit source identifier */
> +#define KVM_DEV_XIVE_GRP_EQ_CONFIG 4 /* 64-bit EQ identifier */
>
> /* Layout of 64-bit XIVE source attribute values */
> #define KVM_XIVE_LEVEL_SENSITIVE (1ULL << 0)
> @@ -696,4 +697,22 @@ struct kvm_ppc_cpu_char {
> #define KVM_XIVE_SOURCE_EISN_SHIFT 33
> #define KVM_XIVE_SOURCE_EISN_MASK 0xfffffffe00000000ULL
>
> +/* Layout of 64-bit EQ identifier */
> +#define KVM_XIVE_EQ_PRIORITY_SHIFT 0
> +#define KVM_XIVE_EQ_PRIORITY_MASK 0x7
> +#define KVM_XIVE_EQ_SERVER_SHIFT 3
> +#define KVM_XIVE_EQ_SERVER_MASK 0xfffffff8ULL
> +
> +/* Layout of EQ configuration values (64 bytes) */
> +struct kvm_ppc_xive_eq {
> + __u32 flags;
> + __u32 qshift;
> + __u64 qaddr;
> + __u32 qtoggle;
> + __u32 qindex;
> + __u8 pad[40];
> +};
> +
> +#define KVM_XIVE_EQ_ALWAYS_NOTIFY 0x00000001
> +
> #endif /* __LINUX_KVM_POWERPC_H */
> diff --git a/arch/powerpc/kvm/book3s_xive.h b/arch/powerpc/kvm/book3s_xive.h
> index ae26fe653d98..622f594d93e1 100644
> --- a/arch/powerpc/kvm/book3s_xive.h
> +++ b/arch/powerpc/kvm/book3s_xive.h
> @@ -272,6 +272,8 @@ 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);
> +int kvmppc_xive_attach_escalation(struct kvm_vcpu *vcpu, u8 prio,
> + bool single_escalation);
>
> #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 e09f3addffe5..c1b7aa7dbc28 100644
> --- a/arch/powerpc/kvm/book3s_xive.c
> +++ b/arch/powerpc/kvm/book3s_xive.c
> @@ -166,7 +166,8 @@ static irqreturn_t xive_esc_irq(int irq, void *data)
> return IRQ_HANDLED;
> }
>
> -static int xive_attach_escalation(struct kvm_vcpu *vcpu, u8 prio)
> +int kvmppc_xive_attach_escalation(struct kvm_vcpu *vcpu, u8 prio,
> + bool single_escalation)
> {
> struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
> struct xive_q *q = &xc->queues[prio];
> @@ -185,7 +186,7 @@ static int xive_attach_escalation(struct kvm_vcpu *vcpu, u8 prio)
> return -EIO;
> }
>
> - if (xc->xive->single_escalation)
> + if (single_escalation)
> name = kasprintf(GFP_KERNEL, "kvm-%d-%d",
> vcpu->kvm->arch.lpid, xc->server_num);
> else
> @@ -217,7 +218,7 @@ static int xive_attach_escalation(struct kvm_vcpu *vcpu, u8 prio)
> * interrupt, thus leaving it effectively masked after
> * it fires once.
> */
> - if (xc->xive->single_escalation) {
> + if (single_escalation) {
> struct irq_data *d = irq_get_irq_data(xc->esc_virq[prio]);
> struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
>
> @@ -291,7 +292,8 @@ static int xive_check_provisioning(struct kvm *kvm, u8 prio)
> continue;
> rc = xive_provision_queue(vcpu, prio);
> if (rc == 0 && !xive->single_escalation)
> - xive_attach_escalation(vcpu, prio);
> + kvmppc_xive_attach_escalation(vcpu, prio,
> + xive->single_escalation);
> if (rc)
> return rc;
> }
> @@ -1214,7 +1216,8 @@ int kvmppc_xive_connect_vcpu(struct kvm_device *dev,
> if (xive->qmap & (1 << i)) {
> r = xive_provision_queue(vcpu, i);
> if (r == 0 && !xive->single_escalation)
> - xive_attach_escalation(vcpu, i);
> + kvmppc_xive_attach_escalation(
> + vcpu, i, xive->single_escalation);
> if (r)
> goto bail;
> } else {
> @@ -1229,7 +1232,7 @@ int kvmppc_xive_connect_vcpu(struct kvm_device *dev,
> }
>
> /* If not done above, attach priority 0 escalation */
> - r = xive_attach_escalation(vcpu, 0);
> + r = kvmppc_xive_attach_escalation(vcpu, 0, xive->single_escalation);
> if (r)
> goto bail;
>
> diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
> index 492825a35958..2c335454da72 100644
> --- a/arch/powerpc/kvm/book3s_xive_native.c
> +++ b/arch/powerpc/kvm/book3s_xive_native.c
> @@ -335,6 +335,236 @@ static int kvmppc_xive_native_set_source_config(struct kvmppc_xive *xive,
> priority, masked, eisn);
> }
>
> +static int xive_native_validate_queue_size(u32 qshift)
> +{
> + /*
> + * We only support 64K pages for the moment. This is also
> + * advertised in the DT property "ibm,xive-eq-sizes"
> + */
> + switch (qshift) {
> + case 0: /* EQ reset */
> + case 16:
> + return 0;
> + case 12:
> + case 21:
> + case 24:
> + default:
> + return -EINVAL;
Now that you're doing a proper test against the guest page size, it
would be very easy to allow this to support things other than a 64kiB
queue. That can be a followup change, though.
> + }
> +}
> +
> +static int kvmppc_xive_native_set_queue_config(struct kvmppc_xive *xive,
> + long eq_idx, u64 addr)
> +{
> + struct kvm *kvm = xive->kvm;
> + struct kvm_vcpu *vcpu;
> + struct kvmppc_xive_vcpu *xc;
> + void __user *ubufp = (void __user *) addr;
> + u32 server;
> + u8 priority;
> + struct kvm_ppc_xive_eq kvm_eq;
> + int rc;
> + __be32 *qaddr = 0;
> + struct page *page;
> + struct xive_q *q;
> + gfn_t gfn;
> + unsigned long page_size;
> +
> + /*
> + * Demangle priority/server tuple from the EQ identifier
> + */
> + priority = (eq_idx & KVM_XIVE_EQ_PRIORITY_MASK) >>
> + KVM_XIVE_EQ_PRIORITY_SHIFT;
> + server = (eq_idx & KVM_XIVE_EQ_SERVER_MASK) >>
> + KVM_XIVE_EQ_SERVER_SHIFT;
> +
> + if (copy_from_user(&kvm_eq, ubufp, sizeof(kvm_eq)))
> + return -EFAULT;
> +
> + vcpu = kvmppc_xive_find_server(kvm, server);
> + if (!vcpu) {
> + pr_err("Can't find server %d\n", server);
> + return -ENOENT;
> + }
> + xc = vcpu->arch.xive_vcpu;
> +
> + if (priority != xive_prio_from_guest(priority)) {
> + pr_err("Trying to restore invalid queue %d for VCPU %d\n",
> + priority, server);
> + return -EINVAL;
> + }
> + q = &xc->queues[priority];
> +
> + pr_devel("%s VCPU %d priority %d fl:%x shift:%d addr:%llx g:%d idx:%d\n",
> + __func__, server, priority, kvm_eq.flags,
> + kvm_eq.qshift, kvm_eq.qaddr, kvm_eq.qtoggle, kvm_eq.qindex);
> +
> + /*
> + * sPAPR specifies a "Unconditional Notify (n) flag" for the
> + * H_INT_SET_QUEUE_CONFIG hcall which forces notification
> + * without using the coalescing mechanisms provided by the
> + * XIVE END ESBs.
> + */
> + if (kvm_eq.flags & ~KVM_XIVE_EQ_ALWAYS_NOTIFY) {
> + pr_err("invalid flags %d\n", kvm_eq.flags);
> + return -EINVAL;
> + }
So this test prevents setting any (as yet undefined) flags other than
EQ_ALWAYS_NOTIFY, which is good. However, AFAICT you never actually
branch based on whether the EQ_ALWAYS_NOTIFY flag is set - you just
assume that it is. You should either actually pass this flag through
to the OPAL call, or have another test here which rejects the ioctl()
if the flag is *not* set.
> +
> + rc = xive_native_validate_queue_size(kvm_eq.qshift);
> + if (rc) {
> + pr_err("invalid queue size %d\n", kvm_eq.qshift);
> + return rc;
> + }
> +
> + /* reset queue and disable queueing */
> + if (!kvm_eq.qshift) {
> + q->guest_qaddr = 0;
> + q->guest_qshift = 0;
> +
> + rc = xive_native_configure_queue(xc->vp_id, q, priority,
> + NULL, 0, true);
> + if (rc) {
> + pr_err("Failed to reset queue %d for VCPU %d: %d\n",
> + priority, xc->server_num, rc);
> + return rc;
> + }
> +
> + if (q->qpage) {
> + put_page(virt_to_page(q->qpage));
> + q->qpage = NULL;
> + }
> +
> + return 0;
> + }
> +
> + gfn = gpa_to_gfn(kvm_eq.qaddr);
> + page = gfn_to_page(kvm, gfn);
> + if (is_error_page(page)) {
> + pr_warn("Couldn't get guest page for %llx!\n", kvm_eq.qaddr);
> + return -EINVAL;
> + }
> +
> + page_size = kvm_host_page_size(kvm, gfn);
> + if (1ull << kvm_eq.qshift > page_size) {
> + pr_warn("Incompatible host page size %lx!\n", page_size);
> + return -EINVAL;
> + }
Sorry.. I should have thought of this earlier. If qaddr isn't aligned
to a (page_size) boundary, this test isn't sufficient - you need to
make sure the whole thing fits within the host page, even if it's
offset.
Alternatively, you could check that qaddr is naturally aligned for the
requested qshift. Possibly that's necessary for the hardware anyway.
> +
> + qaddr = page_to_virt(page) + (kvm_eq.qaddr & ~PAGE_MASK);
> +
> + /*
> + * Backup the queue page guest address to the mark EQ page
> + * dirty for migration.
> + */
> + q->guest_qaddr = kvm_eq.qaddr;
> + q->guest_qshift = kvm_eq.qshift;
> +
> + /*
> + * Unconditional Notification is forced by default at the
> + * OPAL level because the use of END ESBs is not supported by
> + * Linux.
> + */
> + rc = xive_native_configure_queue(xc->vp_id, q, priority,
> + (__be32 *) qaddr, kvm_eq.qshift, true);
> + if (rc) {
> + pr_err("Failed to configure queue %d for VCPU %d: %d\n",
> + priority, xc->server_num, rc);
> + put_page(page);
> + return rc;
> + }
> +
> + /*
> + * Only restore the queue state when needed. When doing the
> + * H_INT_SET_SOURCE_CONFIG hcall, it should not.
> + */
> + if (kvm_eq.qtoggle != 1 || kvm_eq.qindex != 0) {
> + rc = xive_native_set_queue_state(xc->vp_id, priority,
> + kvm_eq.qtoggle,
> + kvm_eq.qindex);
> + if (rc)
> + goto error;
> + }
> +
> + rc = kvmppc_xive_attach_escalation(vcpu, priority,
> + xive->single_escalation);
> +error:
> + if (rc)
> + kvmppc_xive_native_cleanup_queue(vcpu, priority);
> + return rc;
> +}
> +
> +static int kvmppc_xive_native_get_queue_config(struct kvmppc_xive *xive,
> + long eq_idx, u64 addr)
> +{
> + struct kvm *kvm = xive->kvm;
> + struct kvm_vcpu *vcpu;
> + struct kvmppc_xive_vcpu *xc;
> + struct xive_q *q;
> + void __user *ubufp = (u64 __user *) addr;
> + u32 server;
> + u8 priority;
> + struct kvm_ppc_xive_eq kvm_eq;
> + u64 qaddr;
> + u64 qshift;
> + u64 qeoi_page;
> + u32 escalate_irq;
> + u64 qflags;
> + int rc;
> +
> + /*
> + * Demangle priority/server tuple from the EQ identifier
> + */
> + priority = (eq_idx & KVM_XIVE_EQ_PRIORITY_MASK) >>
> + KVM_XIVE_EQ_PRIORITY_SHIFT;
> + server = (eq_idx & KVM_XIVE_EQ_SERVER_MASK) >>
> + KVM_XIVE_EQ_SERVER_SHIFT;
> +
> + vcpu = kvmppc_xive_find_server(kvm, server);
> + if (!vcpu) {
> + pr_err("Can't find server %d\n", server);
> + return -ENOENT;
> + }
> + xc = vcpu->arch.xive_vcpu;
> +
> + if (priority != xive_prio_from_guest(priority)) {
> + pr_err("invalid priority for queue %d for VCPU %d\n",
> + priority, server);
> + return -EINVAL;
> + }
> + q = &xc->queues[priority];
> +
> + memset(&kvm_eq, 0, sizeof(kvm_eq));
> +
> + if (!q->qpage)
> + return 0;
> +
> + rc = xive_native_get_queue_info(xc->vp_id, priority, &qaddr, &qshift,
> + &qeoi_page, &escalate_irq, &qflags);
> + if (rc)
> + return rc;
> +
> + kvm_eq.flags = 0;
> + if (qflags & OPAL_XIVE_EQ_ALWAYS_NOTIFY)
> + kvm_eq.flags |= KVM_XIVE_EQ_ALWAYS_NOTIFY;
> +
> + kvm_eq.qshift = q->guest_qshift;
> + kvm_eq.qaddr = q->guest_qaddr;
> +
> + rc = xive_native_get_queue_state(xc->vp_id, priority, &kvm_eq.qtoggle,
> + &kvm_eq.qindex);
> + if (rc)
> + return rc;
> +
> + pr_devel("%s VCPU %d priority %d fl:%x shift:%d addr:%llx g:%d idx:%d\n",
> + __func__, server, priority, kvm_eq.flags,
> + kvm_eq.qshift, kvm_eq.qaddr, kvm_eq.qtoggle, kvm_eq.qindex);
> +
> + if (copy_to_user(ubufp, &kvm_eq, sizeof(kvm_eq)))
> + return -EFAULT;
> +
> + return 0;
> +}
> +
> static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
> struct kvm_device_attr *attr)
> {
> @@ -349,6 +579,9 @@ static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
> case KVM_DEV_XIVE_GRP_SOURCE_CONFIG:
> return kvmppc_xive_native_set_source_config(xive, attr->attr,
> attr->addr);
> + case KVM_DEV_XIVE_GRP_EQ_CONFIG:
> + return kvmppc_xive_native_set_queue_config(xive, attr->attr,
> + attr->addr);
> }
> return -ENXIO;
> }
> @@ -356,6 +589,13 @@ static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
> static int kvmppc_xive_native_get_attr(struct kvm_device *dev,
> struct kvm_device_attr *attr)
> {
> + struct kvmppc_xive *xive = dev->private;
> +
> + switch (attr->group) {
> + case KVM_DEV_XIVE_GRP_EQ_CONFIG:
> + return kvmppc_xive_native_get_queue_config(xive, attr->attr,
> + attr->addr);
> + }
> return -ENXIO;
> }
>
> @@ -371,6 +611,8 @@ static int kvmppc_xive_native_has_attr(struct kvm_device *dev,
> attr->attr < KVMPPC_XIVE_NR_IRQS)
> return 0;
> break;
> + case KVM_DEV_XIVE_GRP_EQ_CONFIG:
> + return 0;
> }
> return -ENXIO;
> }
> diff --git a/Documentation/virtual/kvm/devices/xive.txt b/Documentation/virtual/kvm/devices/xive.txt
> index 33c64b2cdbe8..8bb5e6e6923a 100644
> --- a/Documentation/virtual/kvm/devices/xive.txt
> +++ b/Documentation/virtual/kvm/devices/xive.txt
> @@ -53,3 +53,37 @@ the legacy interrupt mode, referred as XICS (POWER7/8).
> -ENXIO: CPU event queues not configured or configuration of the
> underlying HW interrupt failed
> -EBUSY: No CPU available to serve interrupt
> +
> + 4. KVM_DEV_XIVE_GRP_EQ_CONFIG (read-write)
> + Configures an event queue of a CPU
> + Attributes:
> + EQ descriptor identifier (64-bit)
> + The EQ descriptor identifier is a tuple (server, priority) :
> + bits: | 63 .... 32 | 31 .. 3 | 2 .. 0
> + values: | unused | server | priority
> + The kvm_device_attr.addr points to :
> + struct kvm_ppc_xive_eq {
> + __u32 flags;
> + __u32 qshift;
> + __u64 qaddr;
> + __u32 qtoggle;
> + __u32 qindex;
> + __u8 pad[40];
> + };
> + - flags: queue flags
> + KVM_XIVE_EQ_ALWAYS_NOTIFY
> + forces notification without using the coalescing mechanism
> + provided by the XIVE END ESBs.
> + - qshift: queue size (power of 2)
> + - qaddr: real address of queue
> + - qtoggle: current queue toggle bit
> + - qindex: current queue index
> + - pad: reserved for future use
> + Errors:
> + -ENOENT: Invalid CPU number
> + -EINVAL: Invalid priority
> + -EINVAL: Invalid flags
> + -EINVAL: Invalid queue size
> + -EINVAL: Invalid queue address
> + -EFAULT: Invalid user pointer for attr->addr.
> + -EIO: Configuration of the underlying HW failed
--
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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