[PATCH v2 04/16] KVM: PPC: Book3S HV: XIVE: add a control to initialize a source
David Gibson
david at gibson.dropbear.id.au
Mon Feb 25 13:10:12 AEDT 2019
On Fri, Feb 22, 2019 at 12:28:28PM +0100, Cédric Le Goater wrote:
> The associated HW interrupt source is simply allocated at the OPAL/HW
> level and then MASKED. KVM only needs to know about its type: LSI or
> MSI.
>
> Signed-off-by: Cédric Le Goater <clg at kaod.org>
> ---
> arch/powerpc/include/uapi/asm/kvm.h | 5 +
> arch/powerpc/kvm/book3s_xive.h | 10 ++
> arch/powerpc/kvm/book3s_xive.c | 8 +-
> arch/powerpc/kvm/book3s_xive_native.c | 114 +++++++++++++++++++++
> Documentation/virtual/kvm/devices/xive.txt | 15 +++
> 5 files changed, 148 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
> index b002c0c67787..a9ad99f2a11b 100644
> --- a/arch/powerpc/include/uapi/asm/kvm.h
> +++ b/arch/powerpc/include/uapi/asm/kvm.h
> @@ -677,5 +677,10 @@ 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 */
> +
> +/* Layout of 64-bit XIVE source attribute values */
> +#define KVM_XIVE_LEVEL_SENSITIVE (1ULL << 0)
> +#define KVM_XIVE_LEVEL_ASSERTED (1ULL << 1)
>
> #endif /* __LINUX_KVM_POWERPC_H */
> diff --git a/arch/powerpc/kvm/book3s_xive.h b/arch/powerpc/kvm/book3s_xive.h
> index bcb1bbcf0359..f22f2d46d0f0 100644
> --- a/arch/powerpc/kvm/book3s_xive.h
> +++ b/arch/powerpc/kvm/book3s_xive.h
> @@ -12,6 +12,13 @@
> #ifdef CONFIG_KVM_XICS
> #include "book3s_xics.h"
>
> +/*
> + * The XIVE IRQ number space is aligned with the XICS IRQ number
> + * space, CPU IPIs being allocated in the first 4K.
We do align these in qemu, but I don't see that the kernel part
cares: as far as it's concerned only one of XICS or XIVE is active at
a time, and the irq numbers are chosen by userspace.
> + */
> +#define KVMPPC_XIVE_FIRST_IRQ 0
> +#define KVMPPC_XIVE_NR_IRQS KVMPPC_XICS_NR_IRQS
> +
> /*
> * State for one guest irq source.
> *
> @@ -253,6 +260,9 @@ extern int (*__xive_vm_h_eoi)(struct kvm_vcpu *vcpu, unsigned long xirr);
> */
> void kvmppc_xive_disable_vcpu_interrupts(struct kvm_vcpu *vcpu);
> 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);
>
> #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 d1cc18a5b1c4..6f950ecb3592 100644
> --- a/arch/powerpc/kvm/book3s_xive.c
> +++ b/arch/powerpc/kvm/book3s_xive.c
I wonder if we should rename this book3s_xics_on_xive.c or something
at some point, I keep getting confused because I forget that this is
only dealing with host xive, not guest xive.
> @@ -1485,8 +1485,8 @@ static int xive_get_source(struct kvmppc_xive *xive, long irq, u64 addr)
> return 0;
> }
>
> -static struct kvmppc_xive_src_block *xive_create_src_block(struct kvmppc_xive *xive,
> - int irq)
> +struct kvmppc_xive_src_block *kvmppc_xive_create_src_block(
> + struct kvmppc_xive *xive, int irq)
> {
> struct kvm *kvm = xive->kvm;
> struct kvmppc_xive_src_block *sb;
It's odd that this function, now used from the xive-on-xive path as
well as the xics-on-xive path references KVMPPC_XICS_ICS_SHIFT a few
lines down from this change.
> @@ -1565,7 +1565,7 @@ static int xive_set_source(struct kvmppc_xive *xive, long irq, u64 addr)
> sb = kvmppc_xive_find_source(xive, irq, &idx);
> if (!sb) {
> pr_devel("No source, creating source block...\n");
> - sb = xive_create_src_block(xive, irq);
> + sb = kvmppc_xive_create_src_block(xive, irq);
> if (!sb) {
> pr_devel("Failed to create block...\n");
> return -ENOMEM;
> @@ -1789,7 +1789,7 @@ static void kvmppc_xive_cleanup_irq(u32 hw_num, struct xive_irq_data *xd)
> xive_cleanup_irq_data(xd);
> }
>
> -static void kvmppc_xive_free_sources(struct kvmppc_xive_src_block *sb)
> +void kvmppc_xive_free_sources(struct kvmppc_xive_src_block *sb)
> {
> int i;
>
> diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
> index 1f3da47a4a6a..a9b2d2d9af99 100644
> --- a/arch/powerpc/kvm/book3s_xive_native.c
> +++ b/arch/powerpc/kvm/book3s_xive_native.c
> @@ -31,6 +31,29 @@
>
> #include "book3s_xive.h"
>
> +/*
> + * TODO: introduce a common template file with the XIVE native layer
> + * and the XICS-on-XIVE glue for the utility functions
> + */
> +#define __x_eoi_page(xd) ((void __iomem *)((xd)->eoi_mmio))
> +#define __x_trig_page(xd) ((void __iomem *)((xd)->trig_mmio))
> +#define __x_readq __raw_readq
> +#define __x_writeq __raw_writeq
> +
> +static u8 xive_vm_esb_load(struct xive_irq_data *xd, u32 offset)
> +{
> + u64 val;
> +
> + if (xd->flags & XIVE_IRQ_FLAG_SHIFT_BUG)
> + offset |= offset << 4;
> +
> + val = __x_readq(__x_eoi_page(xd) + offset);
> +#ifdef __LITTLE_ENDIAN__
> + val >>= 64-8;
> +#endif
> + return (u8)val;
> +}
> +
> static void kvmppc_xive_native_cleanup_queue(struct kvm_vcpu *vcpu, int prio)
> {
> struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
> @@ -153,12 +176,89 @@ int kvmppc_xive_native_connect_vcpu(struct kvm_device *dev,
> return rc;
> }
>
> +static int kvmppc_xive_native_set_source(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;
> + u64 val;
> + u16 idx;
> +
> + pr_devel("%s irq=0x%lx\n", __func__, irq);
> +
> + if (irq < KVMPPC_XIVE_FIRST_IRQ || irq >= KVMPPC_XIVE_NR_IRQS)
> + return -E2BIG;
> +
> + sb = kvmppc_xive_find_source(xive, irq, &idx);
> + if (!sb) {
> + pr_debug("No source, creating source block...\n");
> + sb = kvmppc_xive_create_src_block(xive, irq);
> + if (!sb) {
> + pr_err("Failed to create block...\n");
> + return -ENOMEM;
> + }
> + }
> + state = &sb->irq_state[idx];
> +
> + if (get_user(val, ubufp)) {
> + pr_err("fault getting user info !\n");
> + return -EFAULT;
> + }
You should validate the value loaded here to check it doesn't have any
bits set we don't know about.
> +
> + /*
> + * If the source doesn't already have an IPI, allocate
> + * one and get the corresponding data
> + */
> + if (!state->ipi_number) {
> + state->ipi_number = xive_native_alloc_irq();
> + if (state->ipi_number == 0) {
> + pr_err("Failed to allocate IRQ !\n");
> + return -ENXIO;
> + }
> + xive_native_populate_irq_data(state->ipi_number,
> + &state->ipi_data);
> + pr_debug("%s allocated hw_irq=0x%x for irq=0x%lx\n", __func__,
> + state->ipi_number, irq);
> + }
> +
> + arch_spin_lock(&sb->lock);
Why the direct call to arch_spin_lock() rather than just spin_lock()?
> +
> + /* Restore LSI state */
> + if (val & KVM_XIVE_LEVEL_SENSITIVE) {
> + state->lsi = true;
> + if (val & KVM_XIVE_LEVEL_ASSERTED)
> + state->asserted = true;
> + pr_devel(" LSI ! Asserted=%d\n", state->asserted);
> + }
> +
> + /* Mask IRQ to start with */
> + state->act_server = 0;
> + state->act_priority = MASKED;
> + xive_vm_esb_load(&state->ipi_data, XIVE_ESB_SET_PQ_01);
> + xive_native_configure_irq(state->ipi_number, 0, MASKED, 0);
> +
> + /* Increment the number of valid sources and mark this one valid */
> + if (!state->valid)
> + xive->src_count++;
> + state->valid = true;
> +
> + arch_spin_unlock(&sb->lock);
> +
> + return 0;
> +}
> +
> static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
> struct kvm_device_attr *attr)
> {
> + struct kvmppc_xive *xive = dev->private;
> +
> switch (attr->group) {
> case KVM_DEV_XIVE_GRP_CTRL:
> break;
> + case KVM_DEV_XIVE_GRP_SOURCE:
> + return kvmppc_xive_native_set_source(xive, attr->attr,
> + attr->addr);
> }
> return -ENXIO;
> }
> @@ -175,6 +275,11 @@ static int kvmppc_xive_native_has_attr(struct kvm_device *dev,
> switch (attr->group) {
> case KVM_DEV_XIVE_GRP_CTRL:
> break;
> + case KVM_DEV_XIVE_GRP_SOURCE:
> + if (attr->attr >= KVMPPC_XIVE_FIRST_IRQ &&
> + attr->attr < KVMPPC_XIVE_NR_IRQS)
> + return 0;
> + break;
> }
> return -ENXIO;
> }
> @@ -183,6 +288,7 @@ static void kvmppc_xive_native_free(struct kvm_device *dev)
> {
> struct kvmppc_xive *xive = dev->private;
> struct kvm *kvm = xive->kvm;
> + int i;
>
> debugfs_remove(xive->dentry);
>
> @@ -191,6 +297,14 @@ static void kvmppc_xive_native_free(struct kvm_device *dev)
> if (kvm)
> kvm->arch.xive = NULL;
>
> + /* Mask and free interrupts */
> + for (i = 0; i <= xive->max_sbid; i++) {
> + if (xive->src_blocks[i])
> + kvmppc_xive_free_sources(xive->src_blocks[i]);
> + kfree(xive->src_blocks[i]);
> + xive->src_blocks[i] = NULL;
> + }
> +
> if (xive->vp_base != XIVE_INVALID_VP)
> xive_native_free_vp_block(xive->vp_base);
>
> diff --git a/Documentation/virtual/kvm/devices/xive.txt b/Documentation/virtual/kvm/devices/xive.txt
> index fdbd2ff92a88..cd8bfc37b72e 100644
> --- a/Documentation/virtual/kvm/devices/xive.txt
> +++ b/Documentation/virtual/kvm/devices/xive.txt
> @@ -17,3 +17,18 @@ the legacy interrupt mode, referred as XICS (POWER7/8).
>
> 1. KVM_DEV_XIVE_GRP_CTRL
> Provides global controls on the device
> +
> + 2. KVM_DEV_XIVE_GRP_SOURCE (write only)
> + Initializes a new source in the XIVE device and mask it.
> + Attributes:
> + Interrupt source number (64-bit)
> + The kvm_device_attr.addr points to a __u64 value:
> + bits: | 63 .... 2 | 1 | 0
> + values: | unused | level | type
> + - type: 0:MSI 1:LSI
> + - level: assertion level in case of an LSI.
> + Errors:
> + -E2BIG: Interrupt source number is out of range
> + -ENOMEM: Could not create a new source block
> + -EFAULT: Invalid user pointer for attr->addr.
> + -ENXIO: Could not allocate underlying HW 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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