2022-01-14 23:05:53

by Matthew Rosato

[permalink] [raw]
Subject: [PATCH v2 15/30] KVM: s390: pci: do initial setup for AEN interpretation

Initial setup for Adapter Event Notification Interpretation for zPCI
passthrough devices. Specifically, allocate a structure for forwarding of
adapter events and pass the address of this structure to firmware.

Signed-off-by: Matthew Rosato <[email protected]>
---
arch/s390/include/asm/pci.h | 4 +
arch/s390/include/asm/pci_insn.h | 12 +++
arch/s390/kvm/interrupt.c | 14 +++
arch/s390/kvm/kvm-s390.c | 9 ++
arch/s390/kvm/pci.c | 144 +++++++++++++++++++++++++++++++
arch/s390/kvm/pci.h | 42 +++++++++
arch/s390/pci/pci.c | 6 ++
7 files changed, 231 insertions(+)
create mode 100644 arch/s390/kvm/pci.h

diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 9b6c657d8d31..9ff8dc19975e 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -9,6 +9,7 @@
#include <asm-generic/pci.h>
#include <asm/pci_clp.h>
#include <asm/pci_debug.h>
+#include <asm/pci_insn.h>
#include <asm/sclp.h>

#define PCIBIOS_MIN_IO 0x1000
@@ -204,6 +205,9 @@ extern const struct attribute_group *zpci_attr_groups[];
extern unsigned int s390_pci_force_floating __initdata;
extern unsigned int s390_pci_no_rid;

+extern union zpci_sic_iib *zpci_aipb;
+extern struct airq_iv *zpci_aif_sbv;
+
/* -----------------------------------------------------------------------------
Prototypes
----------------------------------------------------------------------------- */
diff --git a/arch/s390/include/asm/pci_insn.h b/arch/s390/include/asm/pci_insn.h
index 32759c407b8f..ad9000295c82 100644
--- a/arch/s390/include/asm/pci_insn.h
+++ b/arch/s390/include/asm/pci_insn.h
@@ -101,6 +101,7 @@ struct zpci_fib {
/* Set Interruption Controls Operation Controls */
#define SIC_IRQ_MODE_ALL 0
#define SIC_IRQ_MODE_SINGLE 1
+#define SIC_SET_AENI_CONTROLS 2
#define SIC_IRQ_MODE_DIRECT 4
#define SIC_IRQ_MODE_D_ALL 16
#define SIC_IRQ_MODE_D_SINGLE 17
@@ -127,9 +128,20 @@ struct zpci_cdiib {
u64 : 64;
} __packed __aligned(8);

+/* adapter interruption parameters block */
+struct zpci_aipb {
+ u64 faisb;
+ u64 gait;
+ u16 : 13;
+ u16 afi : 3;
+ u32 : 32;
+ u16 faal;
+} __packed __aligned(8);
+
union zpci_sic_iib {
struct zpci_diib diib;
struct zpci_cdiib cdiib;
+ struct zpci_aipb aipb;
};

DECLARE_STATIC_KEY_FALSE(have_mio);
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index f9b872e358c6..a591b8cd662f 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -32,6 +32,7 @@
#include "kvm-s390.h"
#include "gaccess.h"
#include "trace-s390.h"
+#include "pci.h"

#define PFAULT_INIT 0x0600
#define PFAULT_DONE 0x0680
@@ -3278,6 +3279,11 @@ void kvm_s390_gib_destroy(void)
{
if (!gib)
return;
+ if (IS_ENABLED(CONFIG_PCI) && sclp.has_aeni && aift) {
+ mutex_lock(&aift->lock);
+ kvm_s390_pci_aen_exit();
+ mutex_unlock(&aift->lock);
+ }
chsc_sgib(0);
unregister_adapter_interrupt(&gib_alert_irq);
free_page((unsigned long)gib);
@@ -3315,6 +3321,14 @@ int kvm_s390_gib_init(u8 nisc)
goto out_unreg_gal;
}

+ if (IS_ENABLED(CONFIG_PCI) && sclp.has_aeni) {
+ if (kvm_s390_pci_aen_init(nisc)) {
+ pr_err("Initializing AEN for PCI failed\n");
+ rc = -EIO;
+ goto out_unreg_gal;
+ }
+ }
+
KVM_EVENT(3, "gib 0x%pK (nisc=%d) initialized", gib, gib->nisc);
goto out;

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 14a18ba5ff2c..01dc3f6883d0 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -48,6 +48,7 @@
#include <asm/fpu/api.h>
#include "kvm-s390.h"
#include "gaccess.h"
+#include "pci.h"

#define CREATE_TRACE_POINTS
#include "trace.h"
@@ -503,6 +504,14 @@ int kvm_arch_init(void *opaque)
goto out;
}

+ if (IS_ENABLED(CONFIG_PCI)) {
+ rc = kvm_s390_pci_init();
+ if (rc) {
+ pr_err("Unable to allocate AIFT for PCI\n");
+ goto out;
+ }
+ }
+
rc = kvm_s390_gib_init(GAL_ISC);
if (rc)
goto out;
diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
index 1c33bc7bf2bd..dae853da6df1 100644
--- a/arch/s390/kvm/pci.c
+++ b/arch/s390/kvm/pci.c
@@ -10,6 +10,138 @@
#include <linux/kvm_host.h>
#include <linux/pci.h>
#include <asm/kvm_pci.h>
+#include <asm/pci.h>
+#include <asm/pci_insn.h>
+#include "pci.h"
+
+struct zpci_aift *aift;
+
+static inline int __set_irq_noiib(u16 ctl, u8 isc)
+{
+ union zpci_sic_iib iib = {{0}};
+
+ return zpci_set_irq_ctrl(ctl, isc, &iib);
+}
+
+/* Caller must hold the aift lock before calling this function */
+void kvm_s390_pci_aen_exit(void)
+{
+ unsigned long flags;
+ struct kvm_zdev **gait_kzdev;
+
+ /*
+ * Contents of the aipb remain registered for the life of the host
+ * kernel, the information preserved in zpci_aipb and zpci_aif_sbv
+ * in case we insert the KVM module again later. Clear the AIFT
+ * information and free anything not registered with underlying
+ * firmware.
+ */
+ spin_lock_irqsave(&aift->gait_lock, flags);
+ gait_kzdev = aift->kzdev;
+ aift->gait = 0;
+ aift->sbv = 0;
+ aift->kzdev = 0;
+ spin_unlock_irqrestore(&aift->gait_lock, flags);
+
+ kfree(gait_kzdev);
+}
+
+int kvm_s390_pci_aen_init(u8 nisc)
+{
+ struct page *page;
+ int rc = 0, size;
+ bool first = false;
+
+ /* If already enabled for AEN, bail out now */
+ if (aift->gait || aift->sbv)
+ return -EPERM;
+
+ mutex_lock(&aift->lock);
+ aift->kzdev = kcalloc(ZPCI_NR_DEVICES, sizeof(struct kvm_zdev),
+ GFP_KERNEL);
+ if (!aift->kzdev) {
+ rc = -ENOMEM;
+ goto unlock;
+ }
+
+ if (!zpci_aipb) {
+ zpci_aipb = kzalloc(sizeof(union zpci_sic_iib), GFP_KERNEL);
+ if (!zpci_aipb) {
+ rc = -ENOMEM;
+ goto free_zdev;
+ }
+ first = true;
+ aift->sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC, 0);
+ if (!aift->sbv) {
+ rc = -ENOMEM;
+ goto free_aipb;
+ }
+ zpci_aif_sbv = aift->sbv;
+ size = get_order(PAGE_ALIGN(ZPCI_NR_DEVICES *
+ sizeof(struct zpci_gaite)));
+ page = alloc_pages(GFP_KERNEL | __GFP_ZERO, size);
+ if (!page) {
+ rc = -ENOMEM;
+ goto free_sbv;
+ }
+ aift->gait = (struct zpci_gaite *)page_to_phys(page);
+
+ zpci_aipb->aipb.faisb = virt_to_phys(aift->sbv->vector);
+ zpci_aipb->aipb.gait = virt_to_phys(aift->gait);
+ zpci_aipb->aipb.afi = nisc;
+ zpci_aipb->aipb.faal = ZPCI_NR_DEVICES;
+
+ /* Setup Adapter Event Notification Interpretation */
+ if (zpci_set_irq_ctrl(SIC_SET_AENI_CONTROLS, 0, zpci_aipb)) {
+ rc = -EIO;
+ goto free_gait;
+ }
+ } else {
+ /*
+ * AEN registration can only happen once per system boot. If
+ * an aipb already exists then AEN was already registered and
+ * we can re-use the aipb contents. This can only happen if
+ * the KVM module was removed and re-inserted.
+ */
+ if (zpci_aipb->aipb.afi != nisc ||
+ zpci_aipb->aipb.faal != ZPCI_NR_DEVICES) {
+ rc = -EINVAL;
+ goto free_zdev;
+ }
+ aift->sbv = zpci_aif_sbv;
+ aift->gait = (struct zpci_gaite *)zpci_aipb->aipb.gait;
+ }
+
+ /* Enable floating IRQs */
+ if (__set_irq_noiib(SIC_IRQ_MODE_SINGLE, nisc)) {
+ rc = -EIO;
+ kvm_s390_pci_aen_exit();
+ }
+
+ goto unlock;
+
+free_gait:
+ size = get_order(PAGE_ALIGN(ZPCI_NR_DEVICES *
+ sizeof(struct zpci_gaite)));
+ free_pages((unsigned long)aift->gait, size);
+free_sbv:
+ if (first) {
+ /* If AEN setup failed, only free a newly-allocated sbv */
+ airq_iv_release(aift->sbv);
+ zpci_aif_sbv = 0;
+ }
+free_aipb:
+ if (first) {
+ /* If AEN setup failed, only free a newly-allocated aipb */
+ kfree(zpci_aipb);
+ zpci_aipb = 0;
+ }
+free_zdev:
+ kfree(aift->kzdev);
+unlock:
+ mutex_unlock(&aift->lock);
+ return rc;
+}

int kvm_s390_pci_dev_open(struct zpci_dev *zdev)
{
@@ -44,3 +176,15 @@ void kvm_s390_pci_attach_kvm(struct zpci_dev *zdev, struct kvm *kvm)
kzdev->kvm = kvm;
}
EXPORT_SYMBOL_GPL(kvm_s390_pci_attach_kvm);
+
+int kvm_s390_pci_init(void)
+{
+ aift = kzalloc(sizeof(struct zpci_aift), GFP_KERNEL);
+ if (!aift)
+ return -ENOMEM;
+
+ spin_lock_init(&aift->gait_lock);
+ mutex_init(&aift->lock);
+
+ return 0;
+}
diff --git a/arch/s390/kvm/pci.h b/arch/s390/kvm/pci.h
new file mode 100644
index 000000000000..b2000ed7b8c3
--- /dev/null
+++ b/arch/s390/kvm/pci.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * s390 kvm PCI passthrough support
+ *
+ * Copyright IBM Corp. 2021
+ *
+ * Author(s): Matthew Rosato <[email protected]>
+ */
+
+#ifndef __KVM_S390_PCI_H
+#define __KVM_S390_PCI_H
+
+#include <linux/pci.h>
+#include <linux/mutex.h>
+#include <asm/airq.h>
+#include <asm/kvm_pci.h>
+
+struct zpci_gaite {
+ u32 gisa;
+ u8 gisc;
+ u8 count;
+ u8 reserved;
+ u8 aisbo;
+ u64 aisb;
+};
+
+struct zpci_aift {
+ struct zpci_gaite *gait;
+ struct airq_iv *sbv;
+ struct kvm_zdev **kzdev;
+ spinlock_t gait_lock; /* Protects the gait, used during AEN forward */
+ struct mutex lock; /* Protects the other structures in aift */
+};
+
+extern struct zpci_aift *aift;
+
+int kvm_s390_pci_aen_init(u8 nisc);
+void kvm_s390_pci_aen_exit(void);
+
+int kvm_s390_pci_init(void);
+
+#endif /* __KVM_S390_PCI_H */
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 1e939b4cf25e..2a19becbc14c 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -61,6 +61,12 @@ DEFINE_STATIC_KEY_FALSE(have_mio);

static struct kmem_cache *zdev_fmb_cache;

+/* AEN structures that must be preserved over KVM module re-insertion */
+union zpci_sic_iib *zpci_aipb;
+EXPORT_SYMBOL_GPL(zpci_aipb);
+struct airq_iv *zpci_aif_sbv;
+EXPORT_SYMBOL_GPL(zpci_aif_sbv);
+
struct zpci_dev *get_zdev_by_fid(u32 fid)
{
struct zpci_dev *tmp, *zdev = NULL;
--
2.27.0


2022-01-21 19:55:58

by Pierre Morel

[permalink] [raw]
Subject: Re: [PATCH v2 15/30] KVM: s390: pci: do initial setup for AEN interpretation



On 1/14/22 21:31, Matthew Rosato wrote:
> Initial setup for Adapter Event Notification Interpretation for zPCI
> passthrough devices. Specifically, allocate a structure for forwarding of
> adapter events and pass the address of this structure to firmware.
>
> Signed-off-by: Matthew Rosato <[email protected]>
> ---
> arch/s390/include/asm/pci.h | 4 +
> arch/s390/include/asm/pci_insn.h | 12 +++
> arch/s390/kvm/interrupt.c | 14 +++
> arch/s390/kvm/kvm-s390.c | 9 ++
> arch/s390/kvm/pci.c | 144 +++++++++++++++++++++++++++++++
> arch/s390/kvm/pci.h | 42 +++++++++
> arch/s390/pci/pci.c | 6 ++
> 7 files changed, 231 insertions(+)
> create mode 100644 arch/s390/kvm/pci.h
>
> diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
> index 9b6c657d8d31..9ff8dc19975e 100644
> --- a/arch/s390/include/asm/pci.h
> +++ b/arch/s390/include/asm/pci.h
> @@ -9,6 +9,7 @@
> #include <asm-generic/pci.h>
> #include <asm/pci_clp.h>
> #include <asm/pci_debug.h>
> +#include <asm/pci_insn.h>
> #include <asm/sclp.h>
>
> #define PCIBIOS_MIN_IO 0x1000
> @@ -204,6 +205,9 @@ extern const struct attribute_group *zpci_attr_groups[];
> extern unsigned int s390_pci_force_floating __initdata;
> extern unsigned int s390_pci_no_rid;
>
> +extern union zpci_sic_iib *zpci_aipb;
> +extern struct airq_iv *zpci_aif_sbv;
> +
> /* -----------------------------------------------------------------------------
> Prototypes
> ----------------------------------------------------------------------------- */
> diff --git a/arch/s390/include/asm/pci_insn.h b/arch/s390/include/asm/pci_insn.h
> index 32759c407b8f..ad9000295c82 100644
> --- a/arch/s390/include/asm/pci_insn.h
> +++ b/arch/s390/include/asm/pci_insn.h
> @@ -101,6 +101,7 @@ struct zpci_fib {
> /* Set Interruption Controls Operation Controls */
> #define SIC_IRQ_MODE_ALL 0
> #define SIC_IRQ_MODE_SINGLE 1
> +#define SIC_SET_AENI_CONTROLS 2
> #define SIC_IRQ_MODE_DIRECT 4
> #define SIC_IRQ_MODE_D_ALL 16
> #define SIC_IRQ_MODE_D_SINGLE 17
> @@ -127,9 +128,20 @@ struct zpci_cdiib {
> u64 : 64;
> } __packed __aligned(8);
>
> +/* adapter interruption parameters block */
> +struct zpci_aipb {
> + u64 faisb;
> + u64 gait;
> + u16 : 13;
> + u16 afi : 3;
> + u32 : 32;
> + u16 faal;
> +} __packed __aligned(8);
> +
> union zpci_sic_iib {
> struct zpci_diib diib;
> struct zpci_cdiib cdiib;
> + struct zpci_aipb aipb;
> };
>
> DECLARE_STATIC_KEY_FALSE(have_mio);
> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
> index f9b872e358c6..a591b8cd662f 100644
> --- a/arch/s390/kvm/interrupt.c
> +++ b/arch/s390/kvm/interrupt.c
> @@ -32,6 +32,7 @@
> #include "kvm-s390.h"
> #include "gaccess.h"
> #include "trace-s390.h"
> +#include "pci.h"
>
> #define PFAULT_INIT 0x0600
> #define PFAULT_DONE 0x0680
> @@ -3278,6 +3279,11 @@ void kvm_s390_gib_destroy(void)
> {
> if (!gib)
> return;
> + if (IS_ENABLED(CONFIG_PCI) && sclp.has_aeni && aift) {
> + mutex_lock(&aift->lock);
> + kvm_s390_pci_aen_exit();
> + mutex_unlock(&aift->lock);
> + }
> chsc_sgib(0);
> unregister_adapter_interrupt(&gib_alert_irq);
> free_page((unsigned long)gib);
> @@ -3315,6 +3321,14 @@ int kvm_s390_gib_init(u8 nisc)
> goto out_unreg_gal;
> }
>
> + if (IS_ENABLED(CONFIG_PCI) && sclp.has_aeni) {
> + if (kvm_s390_pci_aen_init(nisc)) {
> + pr_err("Initializing AEN for PCI failed\n");
> + rc = -EIO;
> + goto out_unreg_gal;
> + }
> + }
> +
> KVM_EVENT(3, "gib 0x%pK (nisc=%d) initialized", gib, gib->nisc);
> goto out;
>
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 14a18ba5ff2c..01dc3f6883d0 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -48,6 +48,7 @@
> #include <asm/fpu/api.h>
> #include "kvm-s390.h"
> #include "gaccess.h"
> +#include "pci.h"
>
> #define CREATE_TRACE_POINTS
> #include "trace.h"
> @@ -503,6 +504,14 @@ int kvm_arch_init(void *opaque)
> goto out;
> }
>
> + if (IS_ENABLED(CONFIG_PCI)) {
> + rc = kvm_s390_pci_init();
> + if (rc) {
> + pr_err("Unable to allocate AIFT for PCI\n");
> + goto out;
> + }
> + }
> +
> rc = kvm_s390_gib_init(GAL_ISC);
> if (rc)
> goto out;
> diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
> index 1c33bc7bf2bd..dae853da6df1 100644
> --- a/arch/s390/kvm/pci.c
> +++ b/arch/s390/kvm/pci.c
> @@ -10,6 +10,138 @@
> #include <linux/kvm_host.h>
> #include <linux/pci.h>
> #include <asm/kvm_pci.h>
> +#include <asm/pci.h>
> +#include <asm/pci_insn.h>
> +#include "pci.h"
> +
> +struct zpci_aift *aift;
> +
> +static inline int __set_irq_noiib(u16 ctl, u8 isc)
> +{
> + union zpci_sic_iib iib = {{0}};
> +
> + return zpci_set_irq_ctrl(ctl, isc, &iib);
> +}
> +
> +/* Caller must hold the aift lock before calling this function */
> +void kvm_s390_pci_aen_exit(void)
> +{
> + unsigned long flags;
> + struct kvm_zdev **gait_kzdev;
> +
> + /*
> + * Contents of the aipb remain registered for the life of the host
> + * kernel, the information preserved in zpci_aipb and zpci_aif_sbv
> + * in case we insert the KVM module again later. Clear the AIFT
> + * information and free anything not registered with underlying
> + * firmware.
> + */
> + spin_lock_irqsave(&aift->gait_lock, flags);
> + gait_kzdev = aift->kzdev;
> + aift->gait = 0;
> + aift->sbv = 0;
> + aift->kzdev = 0;
> + spin_unlock_irqrestore(&aift->gait_lock, flags);
> +
> + kfree(gait_kzdev);
> +}
> +
> +int kvm_s390_pci_aen_init(u8 nisc)
> +{
> + struct page *page;
> + int rc = 0, size;
> + bool first = false;
> +
> + /* If already enabled for AEN, bail out now */
> + if (aift->gait || aift->sbv)
> + return -EPERM;
> +
> + mutex_lock(&aift->lock);
> + aift->kzdev = kcalloc(ZPCI_NR_DEVICES, sizeof(struct kvm_zdev),
> + GFP_KERNEL);
> + if (!aift->kzdev) {
> + rc = -ENOMEM;
> + goto unlock;
> + }
> +
> + if (!zpci_aipb) {

I think you should externalize all this allocation and setup of aipb
in a dedicated function zpci_setup_aipb()
from here ----->

> + zpci_aipb = kzalloc(sizeof(union zpci_sic_iib), GFP_KERNEL);
> + if (!zpci_aipb) {
> + rc = -ENOMEM;
> + goto free_zdev;
> + }
> + first = true;
> + aift->sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC, 0);
> + if (!aift->sbv) {
> + rc = -ENOMEM;
> + goto free_aipb;
> + }
> + zpci_aif_sbv = aift->sbv;
> + size = get_order(PAGE_ALIGN(ZPCI_NR_DEVICES *
> + sizeof(struct zpci_gaite)));
> + page = alloc_pages(GFP_KERNEL | __GFP_ZERO, size);
> + if (!page) {
> + rc = -ENOMEM;
> + goto free_sbv;
> + }
> + aift->gait = (struct zpci_gaite *)page_to_phys(page);
> +
> + zpci_aipb->aipb.faisb = virt_to_phys(aift->sbv->vector);
> + zpci_aipb->aipb.gait = virt_to_phys(aift->gait);
> + zpci_aipb->aipb.afi = nisc;
> + zpci_aipb->aipb.faal = ZPCI_NR_DEVICES;
> +
> + /* Setup Adapter Event Notification Interpretation */
> + if (zpci_set_irq_ctrl(SIC_SET_AENI_CONTROLS, 0, zpci_aipb)) {
> + rc = -EIO;
> + goto free_gait;

to here---->

> + }
> + } else {
> + /*
> + * AEN registration can only happen once per system boot. If
> + * an aipb already exists then AEN was already registered and
> + * we can re-use the aipb contents. This can only happen if
> + * the KVM module was removed and re-inserted.
> + */
> + if (zpci_aipb->aipb.afi != nisc ||
> + zpci_aipb->aipb.faal != ZPCI_NR_DEVICES) {
> + rc = -EINVAL;
> + goto free_zdev;
> + }
> + aift->sbv = zpci_aif_sbv;
> + aift->gait = (struct zpci_gaite *)zpci_aipb->aipb.gait;
> + }
> +
> + /* Enable floating IRQs */
> + if (__set_irq_noiib(SIC_IRQ_MODE_SINGLE, nisc)) {
> + rc = -EIO;
> + kvm_s390_pci_aen_exit();
> + }
> +
> + goto unlock;

and the according errors

here ---->
> +
> +free_gait:
> + size = get_order(PAGE_ALIGN(ZPCI_NR_DEVICES *
> + sizeof(struct zpci_gaite)));
> + free_pages((unsigned long)aift->gait, size);
> +free_sbv:
> + if (first) {
> + /* If AEN setup failed, only free a newly-allocated sbv */
> + airq_iv_release(aift->sbv);
> + zpci_aif_sbv = 0;
> + }
> +free_aipb:
> + if (first) {
> + /* If AEN setup failed, only free a newly-allocated aipb */
> + kfree(zpci_aipb);
> + zpci_aipb = 0;
> + }

to here ---->

To simplify the understanding.

> +free_zdev:
> + kfree(aift->kzdev);
> +unlock:
> + mutex_unlock(&aift->lock);
> + return rc;
> +}
>

... snip...

The second part of the if(aipb) else
could also be externalise in zpci_reset_aipb()

which leads to

if(!aipb)
ret = zpci_setup_aipb()
else
ret = zpci_reset_aipb()

if (ret)
goto cleanup;

enable_irq()
goto unlock;

I think that if we can do that it would be much clearer.
what do you think?

--
Pierre Morel
IBM Lab Boeblingen

2022-01-21 20:01:59

by Matthew Rosato

[permalink] [raw]
Subject: Re: [PATCH v2 15/30] KVM: s390: pci: do initial setup for AEN interpretation

On 1/19/22 1:06 PM, Pierre Morel wrote:
>
>
> On 1/14/22 21:31, Matthew Rosato wrote:
>> Initial setup for Adapter Event Notification Interpretation for zPCI
>> passthrough devices.  Specifically, allocate a structure for
>> forwarding of
>> adapter events and pass the address of this structure to firmware.
>>
>> Signed-off-by: Matthew Rosato <[email protected]>
>> ---
>>   arch/s390/include/asm/pci.h      |   4 +
>>   arch/s390/include/asm/pci_insn.h |  12 +++
>>   arch/s390/kvm/interrupt.c        |  14 +++
>>   arch/s390/kvm/kvm-s390.c         |   9 ++
>>   arch/s390/kvm/pci.c              | 144 +++++++++++++++++++++++++++++++
>>   arch/s390/kvm/pci.h              |  42 +++++++++
>>   arch/s390/pci/pci.c              |   6 ++
>>   7 files changed, 231 insertions(+)
>>   create mode 100644 arch/s390/kvm/pci.h
>>
>> diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
>> index 9b6c657d8d31..9ff8dc19975e 100644
>> --- a/arch/s390/include/asm/pci.h
>> +++ b/arch/s390/include/asm/pci.h
>> @@ -9,6 +9,7 @@
>>   #include <asm-generic/pci.h>
>>   #include <asm/pci_clp.h>
>>   #include <asm/pci_debug.h>
>> +#include <asm/pci_insn.h>
>>   #include <asm/sclp.h>
>>   #define PCIBIOS_MIN_IO        0x1000
>> @@ -204,6 +205,9 @@ extern const struct attribute_group
>> *zpci_attr_groups[];
>>   extern unsigned int s390_pci_force_floating __initdata;
>>   extern unsigned int s390_pci_no_rid;
>> +extern union zpci_sic_iib *zpci_aipb;
>> +extern struct airq_iv *zpci_aif_sbv;
>> +
>>   /*
>> -----------------------------------------------------------------------------
>>
>>     Prototypes
>>
>> -----------------------------------------------------------------------------
>> */
>> diff --git a/arch/s390/include/asm/pci_insn.h
>> b/arch/s390/include/asm/pci_insn.h
>> index 32759c407b8f..ad9000295c82 100644
>> --- a/arch/s390/include/asm/pci_insn.h
>> +++ b/arch/s390/include/asm/pci_insn.h
>> @@ -101,6 +101,7 @@ struct zpci_fib {
>>   /* Set Interruption Controls Operation Controls  */
>>   #define    SIC_IRQ_MODE_ALL        0
>>   #define    SIC_IRQ_MODE_SINGLE        1
>> +#define    SIC_SET_AENI_CONTROLS        2
>>   #define    SIC_IRQ_MODE_DIRECT        4
>>   #define    SIC_IRQ_MODE_D_ALL        16
>>   #define    SIC_IRQ_MODE_D_SINGLE        17
>> @@ -127,9 +128,20 @@ struct zpci_cdiib {
>>       u64 : 64;
>>   } __packed __aligned(8);
>> +/* adapter interruption parameters block */
>> +struct zpci_aipb {
>> +    u64 faisb;
>> +    u64 gait;
>> +    u16 : 13;
>> +    u16 afi : 3;
>> +    u32 : 32;
>> +    u16 faal;
>> +} __packed __aligned(8);
>> +
>>   union zpci_sic_iib {
>>       struct zpci_diib diib;
>>       struct zpci_cdiib cdiib;
>> +    struct zpci_aipb aipb;
>>   };
>>   DECLARE_STATIC_KEY_FALSE(have_mio);
>> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
>> index f9b872e358c6..a591b8cd662f 100644
>> --- a/arch/s390/kvm/interrupt.c
>> +++ b/arch/s390/kvm/interrupt.c
>> @@ -32,6 +32,7 @@
>>   #include "kvm-s390.h"
>>   #include "gaccess.h"
>>   #include "trace-s390.h"
>> +#include "pci.h"
>>   #define PFAULT_INIT 0x0600
>>   #define PFAULT_DONE 0x0680
>> @@ -3278,6 +3279,11 @@ void kvm_s390_gib_destroy(void)
>>   {
>>       if (!gib)
>>           return;
>> +    if (IS_ENABLED(CONFIG_PCI) && sclp.has_aeni && aift) {
>> +        mutex_lock(&aift->lock);
>> +        kvm_s390_pci_aen_exit();
>> +        mutex_unlock(&aift->lock);
>> +    }
>>       chsc_sgib(0);
>>       unregister_adapter_interrupt(&gib_alert_irq);
>>       free_page((unsigned long)gib);
>> @@ -3315,6 +3321,14 @@ int kvm_s390_gib_init(u8 nisc)
>>           goto out_unreg_gal;
>>       }
>> +    if (IS_ENABLED(CONFIG_PCI) && sclp.has_aeni) {
>> +        if (kvm_s390_pci_aen_init(nisc)) {
>> +            pr_err("Initializing AEN for PCI failed\n");
>> +            rc = -EIO;
>> +            goto out_unreg_gal;
>> +        }
>> +    }
>> +
>>       KVM_EVENT(3, "gib 0x%pK (nisc=%d) initialized", gib, gib->nisc);
>>       goto out;
>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>> index 14a18ba5ff2c..01dc3f6883d0 100644
>> --- a/arch/s390/kvm/kvm-s390.c
>> +++ b/arch/s390/kvm/kvm-s390.c
>> @@ -48,6 +48,7 @@
>>   #include <asm/fpu/api.h>
>>   #include "kvm-s390.h"
>>   #include "gaccess.h"
>> +#include "pci.h"
>>   #define CREATE_TRACE_POINTS
>>   #include "trace.h"
>> @@ -503,6 +504,14 @@ int kvm_arch_init(void *opaque)
>>           goto out;
>>       }
>> +    if (IS_ENABLED(CONFIG_PCI)) {
>> +        rc = kvm_s390_pci_init();
>> +        if (rc) {
>> +            pr_err("Unable to allocate AIFT for PCI\n");
>> +            goto out;
>> +        }
>> +    }
>> +
>>       rc = kvm_s390_gib_init(GAL_ISC);
>>       if (rc)
>>           goto out;
>> diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
>> index 1c33bc7bf2bd..dae853da6df1 100644
>> --- a/arch/s390/kvm/pci.c
>> +++ b/arch/s390/kvm/pci.c
>> @@ -10,6 +10,138 @@
>>   #include <linux/kvm_host.h>
>>   #include <linux/pci.h>
>>   #include <asm/kvm_pci.h>
>> +#include <asm/pci.h>
>> +#include <asm/pci_insn.h>
>> +#include "pci.h"
>> +
>> +struct zpci_aift *aift;
>> +
>> +static inline int __set_irq_noiib(u16 ctl, u8 isc)
>> +{
>> +    union zpci_sic_iib iib = {{0}};
>> +
>> +    return zpci_set_irq_ctrl(ctl, isc, &iib);
>> +}
>> +
>> +/* Caller must hold the aift lock before calling this function */
>> +void kvm_s390_pci_aen_exit(void)
>> +{
>> +    unsigned long flags;
>> +    struct kvm_zdev **gait_kzdev;
>> +
>> +    /*
>> +     * Contents of the aipb remain registered for the life of the host
>> +     * kernel, the information preserved in zpci_aipb and zpci_aif_sbv
>> +     * in case we insert the KVM module again later.  Clear the AIFT
>> +     * information and free anything not registered with underlying
>> +     * firmware.
>> +     */
>> +    spin_lock_irqsave(&aift->gait_lock, flags);
>> +    gait_kzdev = aift->kzdev;
>> +    aift->gait = 0;
>> +    aift->sbv = 0;
>> +    aift->kzdev = 0;
>> +    spin_unlock_irqrestore(&aift->gait_lock, flags);
>> +
>> +    kfree(gait_kzdev);
>> +}
>> +
>> +int kvm_s390_pci_aen_init(u8 nisc)
>> +{
>> +    struct page *page;
>> +    int rc = 0, size;
>> +    bool first = false;
>> +
>> +    /* If already enabled for AEN, bail out now */
>> +    if (aift->gait || aift->sbv)
>> +        return -EPERM;
>> +
>> +    mutex_lock(&aift->lock);
>> +    aift->kzdev = kcalloc(ZPCI_NR_DEVICES, sizeof(struct kvm_zdev),
>> +                  GFP_KERNEL);
>> +    if (!aift->kzdev) {
>> +        rc = -ENOMEM;
>> +        goto unlock;
>> +    }
>> +
>> +    if (!zpci_aipb) {
>
> I think you should externalize all this allocation and setup of aipb
> in a dedicated function zpci_setup_aipb()
> from here ----->
>
>> +        zpci_aipb = kzalloc(sizeof(union zpci_sic_iib), GFP_KERNEL);
>> +        if (!zpci_aipb) {
>> +            rc = -ENOMEM;
>> +            goto free_zdev;
>> +        }
>> +        first = true;
>> +        aift->sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC, 0);
>> +        if (!aift->sbv) {
>> +            rc = -ENOMEM;
>> +            goto free_aipb;
>> +        }
>> +        zpci_aif_sbv = aift->sbv;
>> +        size = get_order(PAGE_ALIGN(ZPCI_NR_DEVICES *
>> +                        sizeof(struct zpci_gaite)));
>> +        page = alloc_pages(GFP_KERNEL | __GFP_ZERO, size);
>> +        if (!page) {
>> +            rc = -ENOMEM;
>> +            goto free_sbv;
>> +        }
>> +        aift->gait = (struct zpci_gaite *)page_to_phys(page);
>> +
>> +        zpci_aipb->aipb.faisb = virt_to_phys(aift->sbv->vector);
>> +        zpci_aipb->aipb.gait = virt_to_phys(aift->gait);
>> +        zpci_aipb->aipb.afi = nisc;
>> +        zpci_aipb->aipb.faal = ZPCI_NR_DEVICES;
>> +
>> +        /* Setup Adapter Event Notification Interpretation */
>> +        if (zpci_set_irq_ctrl(SIC_SET_AENI_CONTROLS, 0, zpci_aipb)) {
>> +            rc = -EIO;
>> +            goto free_gait;
>
> to here---->
>
>> +        }
>> +    } else {
>> +        /*
>> +         * AEN registration can only happen once per system boot.  If
>> +         * an aipb already exists then AEN was already registered and
>> +         * we can re-use the aipb contents.  This can only happen if
>> +         * the KVM module was removed and re-inserted.
>> +         */
>> +        if (zpci_aipb->aipb.afi != nisc ||
>> +            zpci_aipb->aipb.faal != ZPCI_NR_DEVICES) {
>> +            rc = -EINVAL;
>> +            goto free_zdev;
>> +        }
>> +        aift->sbv = zpci_aif_sbv;
>> +        aift->gait = (struct zpci_gaite *)zpci_aipb->aipb.gait;
>> +    }
>> +
>> +    /* Enable floating IRQs */
>> +    if (__set_irq_noiib(SIC_IRQ_MODE_SINGLE, nisc)) {
>> +        rc = -EIO;
>> +        kvm_s390_pci_aen_exit();
>> +    }
>> +
>> +    goto unlock;
>
> and the according errors
>
> here ---->
>> +
>> +free_gait:
>> +    size = get_order(PAGE_ALIGN(ZPCI_NR_DEVICES *
>> +                    sizeof(struct zpci_gaite)));
>> +    free_pages((unsigned long)aift->gait, size);
>> +free_sbv:
>> +    if (first) {
>> +        /* If AEN setup failed, only free a newly-allocated sbv */
>> +        airq_iv_release(aift->sbv);
>> +        zpci_aif_sbv = 0;
>> +    }
>> +free_aipb:
>> +    if (first) {
>> +        /* If AEN setup failed, only free a newly-allocated aipb */
>> +        kfree(zpci_aipb);
>> +        zpci_aipb = 0;
>> +    }
>
> to here ---->
>
> To simplify the understanding.
>
>> +free_zdev:
>> +    kfree(aift->kzdev);
>> +unlock:
>> +    mutex_unlock(&aift->lock);
>> +    return rc;
>> +}
>>
>
> ... snip...
>
> The second part of the if(aipb) else
> could also be externalise in zpci_reset_aipb()
>
> which leads to
>
>    if(!aipb)
>     ret = zpci_setup_aipb()
>    else
>     ret = zpci_reset_aipb()
>
>    if (ret)
>     goto cleanup;
>
>     enable_irq()
>     goto unlock;
>
> I think that if we can do that it would be much clearer.
> what do you think?
>

Yup, that sounds good, I will re-organize with 2 new static functions
zpci_setup_aipb() and zpci_reset_aipb()

2022-01-25 16:53:09

by Pierre Morel

[permalink] [raw]
Subject: Re: [PATCH v2 15/30] KVM: s390: pci: do initial setup for AEN interpretation



On 1/14/22 21:31, Matthew Rosato wrote:
> Initial setup for Adapter Event Notification Interpretation for zPCI
> passthrough devices. Specifically, allocate a structure for forwarding of
> adapter events and pass the address of this structure to firmware.
>
> Signed-off-by: Matthew Rosato <[email protected]>
> ---
> arch/s390/include/asm/pci.h | 4 +
> arch/s390/include/asm/pci_insn.h | 12 +++
> arch/s390/kvm/interrupt.c | 14 +++
> arch/s390/kvm/kvm-s390.c | 9 ++
> arch/s390/kvm/pci.c | 144 +++++++++++++++++++++++++++++++
> arch/s390/kvm/pci.h | 42 +++++++++
> arch/s390/pci/pci.c | 6 ++
> 7 files changed, 231 insertions(+)
> create mode 100644 arch/s390/kvm/pci.h
>
...snip...

> new file mode 100644
> index 000000000000..b2000ed7b8c3
> --- /dev/null
> +++ b/arch/s390/kvm/pci.h
> @@ -0,0 +1,42 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * s390 kvm PCI passthrough support
> + *
> + * Copyright IBM Corp. 2021
> + *
> + * Author(s): Matthew Rosato <[email protected]>
> + */
> +
> +#ifndef __KVM_S390_PCI_H
> +#define __KVM_S390_PCI_H
> +
> +#include <linux/pci.h>
> +#include <linux/mutex.h>
> +#include <asm/airq.h>
> +#include <asm/kvm_pci.h>
> +
> +struct zpci_gaite {
> + u32 gisa;
> + u8 gisc;
> + u8 count;
> + u8 reserved;
> + u8 aisbo;
> + u64 aisb;
> +};
> +
> +struct zpci_aift {
> + struct zpci_gaite *gait;
> + struct airq_iv *sbv;
> + struct kvm_zdev **kzdev;
> + spinlock_t gait_lock; /* Protects the gait, used during AEN forward */
> + struct mutex lock; /* Protects the other structures in aift */

To facilitate review and debug, can we please rename the lock aift_lock?


> +};
> +
> +extern struct zpci_aift *aift;
> +
...snip...


--
Pierre Morel
IBM Lab Boeblingen

2022-01-25 22:46:07

by Matthew Rosato

[permalink] [raw]
Subject: Re: [PATCH v2 15/30] KVM: s390: pci: do initial setup for AEN interpretation

On 1/25/22 7:23 AM, Pierre Morel wrote:
>
>
> On 1/14/22 21:31, Matthew Rosato wrote:
>> Initial setup for Adapter Event Notification Interpretation for zPCI
>> passthrough devices.  Specifically, allocate a structure for
>> forwarding of
>> adapter events and pass the address of this structure to firmware.
>>
>> Signed-off-by: Matthew Rosato <[email protected]>
>> ---
>>   arch/s390/include/asm/pci.h      |   4 +
>>   arch/s390/include/asm/pci_insn.h |  12 +++
>>   arch/s390/kvm/interrupt.c        |  14 +++
>>   arch/s390/kvm/kvm-s390.c         |   9 ++
>>   arch/s390/kvm/pci.c              | 144 +++++++++++++++++++++++++++++++
>>   arch/s390/kvm/pci.h              |  42 +++++++++
>>   arch/s390/pci/pci.c              |   6 ++
>>   7 files changed, 231 insertions(+)
>>   create mode 100644 arch/s390/kvm/pci.h
>>
> ...snip...
>
>> new file mode 100644
>> index 000000000000..b2000ed7b8c3
>> --- /dev/null
>> +++ b/arch/s390/kvm/pci.h
>> @@ -0,0 +1,42 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * s390 kvm PCI passthrough support
>> + *
>> + * Copyright IBM Corp. 2021
>> + *
>> + *    Author(s): Matthew Rosato <[email protected]>
>> + */
>> +
>> +#ifndef __KVM_S390_PCI_H
>> +#define __KVM_S390_PCI_H
>> +
>> +#include <linux/pci.h>
>> +#include <linux/mutex.h>
>> +#include <asm/airq.h>
>> +#include <asm/kvm_pci.h>
>> +
>> +struct zpci_gaite {
>> +    u32 gisa;
>> +    u8 gisc;
>> +    u8 count;
>> +    u8 reserved;
>> +    u8 aisbo;
>> +    u64 aisb;
>> +};
>> +
>> +struct zpci_aift {
>> +    struct zpci_gaite *gait;
>> +    struct airq_iv *sbv;
>> +    struct kvm_zdev **kzdev;
>> +    spinlock_t gait_lock; /* Protects the gait, used during AEN
>> forward */
>> +    struct mutex lock; /* Protects the other structures in aift */
>
> To facilitate review and debug, can we please rename the lock aift_lock?
>
>

OK, sure