Re: [PATCH v2 15/30] KVM: s390: pci: do initial setup for AEN interpretation
From: Pierre Morel
Date: Wed Jan 19 2022 - 13:04:55 EST
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 <mjrosato@xxxxxxxxxxxxx>
---
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