[PATCH 14/32] KVM: s390: pci: do initial setup for AEN interpretation

Matthew Rosato
2021-12-07T20:59:19Z

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 <mjrosato@linux.ibm.com>
---
arch/s390/include/asm/pci_insn.h | 12 ++++
arch/s390/kvm/interrupt.c | 17 +++++
arch/s390/kvm/kvm-s390.c | 3 +
arch/s390/kvm/pci.c | 113 +++++++++++++++++++++++++++++++
arch/s390/kvm/pci.h | 42 ++++++++++++
5 files changed, 187 insertions(+)
create mode 100644 arch/s390/kvm/pci.h

diff --git a/arch/s390/include/asm/pci_insn.h b/arch/s390/include/asm/pci_insn.h
index 5331082fa516..e5f57cfe1d45 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..4efe0e95a40f 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
@@ -3276,8 +3277,16 @@ static struct airq_struct gib_alert_irq = {

void kvm_s390_gib_destroy(void)
{
+ struct zpci_aift *aift;
+
if (!gib)
return;
+ aift = kvm_s390_pci_get_aift();
+ if (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 +3324,14 @@ 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..9cd3c8eb59e8 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 +504,8 @@ int kvm_arch_init(void *opaque)
goto out;
}

+ kvm_s390_pci_init();
+
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 ecfc458a5b39..f0e5386ff943 100644
--- a/arch/s390/kvm/pci.c
+++ b/arch/s390/kvm/pci.c
@@ -10,6 +10,113 @@
#include <linux/kvm_host.h>
#include <linux/pci.h>
#include <asm/kvm_pci.h>
+#include "pci.h"
+
+static 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);
+}
+
+struct zpci_aift *kvm_s390_pci_get_aift(void)
+{
+ return &aift;
+}
+
+/* Caller must hold the aift lock before calling this function */
+void kvm_s390_pci_aen_exit(void)
+{
+ struct zpci_gaite *gait;
+ unsigned long flags;
+ struct airq_iv *sbv;
+ struct kvm_zdev **gait_kzdev;
+ int size;
+
+ /* Clear the GAIT and forwarding summary vector */
+ __set_irq_noiib(SIC_SET_AENI_CONTROLS, 0);
+
+ spin_lock_irqsave(&aift.gait_lock, flags);
+ gait = aift.gait;
+ sbv = aift.sbv;
+ gait_kzdev = aift.kzdev;
+ aift.gait = 0;
+ aift.sbv = 0;
+ aift.kzdev = 0;
+ spin_unlock_irqrestore(&aift.gait_lock, flags);
+
+ if (sbv)
+ airq_iv_release(sbv);
+ size = get_order(PAGE_ALIGN(ZPCI_NR_DEVICES *
+ sizeof(struct zpci_gaite)));
+ free_pages((unsigned long)gait, size);
+ kfree(gait_kzdev);
+}
+
+int kvm_s390_pci_aen_init(u8 nisc)
+{
+ union zpci_sic_iib iib = {{0}};
+ struct page *page;
+ int rc = 0, size;
+
+ /* 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;
+ }
+ aift.sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC, 0);
+ if (!aift.sbv) {
+ rc = -ENOMEM;
+ goto free_zdev;
+ }
+ 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);
+
+ iib.aipb.faisb = (u64)aift.sbv->vector;
+ iib.aipb.gait = (u64)aift.gait;
+ iib.aipb.afi = nisc;
+ iib.aipb.faal = ZPCI_NR_DEVICES;
+
+ /* Setup Adapter Event Notification Interpretation */
+ if (zpci_set_irq_ctrl(SIC_SET_AENI_CONTROLS, 0, &iib)) {
+ rc = -EIO;
+ goto free_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:
+ airq_iv_release(aift.sbv);
+free_zdev:
+ kfree(aift.kzdev);
+unlock:
+ mutex_unlock(&aift.lock);
+ return rc;
+}

int kvm_s390_pci_dev_open(struct zpci_dev *zdev)
{
@@ -55,3 +162,9 @@ int kvm_s390_pci_attach_kvm(struct zpci_dev *zdev, struct kvm *kvm)
return 0;
}
EXPORT_SYMBOL_GPL(kvm_s390_pci_attach_kvm);
+
+void kvm_s390_pci_init(void)
+{
+ spin_lock_init(&aift.gait_lock);
+ mutex_init(&aift.lock);
+}
diff --git a/arch/s390/kvm/pci.h b/arch/s390/kvm/pci.h
new file mode 100644
index 000000000000..74b06d39be3b
--- /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 <mjrosato@linux.ibm.com>
+ */
+
+#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 {
+ unsigned int gisa;
+ u8 gisc;
+ u8 count;
+ u8 reserved;
+ u8 aisbo;
+ unsigned long 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 */
+};
+
+struct zpci_aift *kvm_s390_pci_get_aift(void);
+
+int kvm_s390_pci_aen_init(u8 nisc);
+void kvm_s390_pci_aen_exit(void);
+
+void kvm_s390_pci_init(void);
+
+#endif /* __KVM_S390_PCI_H */
--
2.27.0