On 12/7/21 21:57, Matthew Rosato wrote:
Add a routine that will perform a shadow operation between a guest
and host IOAT. A subsequent patch will invoke this in response to
an 04 RPCIT instruction intercept.
Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
---
arch/s390/include/asm/kvm_pci.h | 1 +
arch/s390/include/asm/pci_dma.h | 1 +
arch/s390/kvm/pci.c | 191 ++++++++++++++++++++++++++++++++
arch/s390/kvm/pci.h | 4 +-
4 files changed, 196 insertions(+), 1 deletion(-)
diff --git a/arch/s390/include/asm/kvm_pci.h b/arch/s390/include/asm/kvm_pci.h
index 254275399f21..97e3a369135d 100644
--- a/arch/s390/include/asm/kvm_pci.h
+++ b/arch/s390/include/asm/kvm_pci.h
@@ -30,6 +30,7 @@ struct kvm_zdev_ioat {
struct kvm_zdev {
struct zpci_dev *zdev;
struct kvm *kvm;
+ u64 rpcit_count;
struct kvm_zdev_ioat ioat;
struct zpci_fib fib;
};
diff --git a/arch/s390/include/asm/pci_dma.h b/arch/s390/include/asm/pci_dma.h
index e1d3c1d3fc8a..0ca15e5db3d9 100644
--- a/arch/s390/include/asm/pci_dma.h
+++ b/arch/s390/include/asm/pci_dma.h
@@ -52,6 +52,7 @@ enum zpci_ioat_dtype {
#define ZPCI_TABLE_ENTRIES (ZPCI_TABLE_SIZE / ZPCI_TABLE_ENTRY_SIZE)
#define ZPCI_TABLE_PAGES (ZPCI_TABLE_SIZE >> PAGE_SHIFT)
#define ZPCI_TABLE_ENTRIES_PAGES (ZPCI_TABLE_ENTRIES * ZPCI_TABLE_PAGES)
+#define ZPCI_TABLE_ENTRIES_PER_PAGE (ZPCI_TABLE_ENTRIES / ZPCI_TABLE_PAGES)
#define ZPCI_TABLE_BITS 11
#define ZPCI_PT_BITS 8
diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
index a1c0c0881332..858c5ecdc8b9 100644
--- a/arch/s390/kvm/pci.c
+++ b/arch/s390/kvm/pci.c
@@ -123,6 +123,195 @@ int kvm_s390_pci_aen_init(u8 nisc)
return rc;
}
...snip...
+
+int kvm_s390_pci_refresh_trans(struct kvm_vcpu *vcpu, unsigned long req,
+ unsigned long start, unsigned long size)
+{
+ struct zpci_dev *zdev;
+ u32 fh;
+ int rc;
+
+ /* If the device has a SHM bit on, let userspace take care of this */
+ fh = req >> 32;
+ if ((fh & aift.mdd) != 0)
+ return -EOPNOTSUPP;
I think you should make this check in the caller.
+
+ /* Make sure this is a valid device associated with this guest */
+ zdev = get_zdev_by_fh(fh);
+ if (!zdev || !zdev->kzdev || zdev->kzdev->kvm != vcpu->kvm)
+ return -EINVAL;
+
+ /* Only proceed if the device is using the assist */
+ if (zdev->kzdev->ioat.head[0] == 0)
+ return -EOPNOTSUPP;
Using the assist means using interpretation over using interception and
legacy vfio-pci. right?
+
+ rc = dma_table_shadow(vcpu, zdev, start, size);
+ if (rc > 0)
+ rc = zpci_refresh_trans((u64) zdev->fh << 32, start, size);
Here you lose the status reported by the hardware.
You should directly use __rpcit(fn, addr, range, &status);
+ zdev->kzdev->rpcit_count++;
+
+ return rc;
+}
+
/* Modify PCI: Register floating adapter interruption forwarding */
static int kvm_zpci_set_airq(struct zpci_dev *zdev)
{
@@ -590,4 +779,6 @@ void kvm_s390_pci_init(void)
{
spin_lock_init(&aift.gait_lock);
mutex_init(&aift.lock);
+
+ WARN_ON(zpci_get_mdd(&aift.mdd));
}
diff --git a/arch/s390/kvm/pci.h b/arch/s390/kvm/pci.h
index 3c86888fe1b3..d252a631b693 100644
--- a/arch/s390/kvm/pci.h
+++ b/arch/s390/kvm/pci.h
@@ -33,6 +33,7 @@ struct zpci_aift {
struct kvm_zdev **kzdev;
spinlock_t gait_lock; /* Protects the gait, used during AEN forward */
struct mutex lock; /* Protects the other structures in aift */
+ u32 mdd;
};
static inline struct kvm *kvm_s390_pci_si_to_kvm(struct zpci_aift *aift,
@@ -47,7 +48,8 @@ struct zpci_aift *kvm_s390_pci_get_aift(void);
int kvm_s390_pci_aen_init(u8 nisc);
void kvm_s390_pci_aen_exit(void);
-
+int kvm_s390_pci_refresh_trans(struct kvm_vcpu *vcpu, unsigned long req,
+ unsigned long start, unsigned long end);
void kvm_s390_pci_init(void);
#endif /* __KVM_S390_PCI_H */
--
Pierre Morel
IBM Lab Boeblingen
