2022-03-14 22:45:27

by Matthew Rosato

[permalink] [raw]
Subject: [PATCH v4 25/32] KVM: s390: pci: provide routines for enabling/disabling IOAT assist

These routines will be wired into a kvm ioctl in orer to respond to
requests to enable / disable a device for PCI I/O Address Translation
assistance via a KVM-managed IOMMU.

Signed-off-by: Matthew Rosato <[email protected]>
---
arch/s390/include/asm/kvm_pci.h | 2 ++
arch/s390/kvm/pci.c | 25 +++++++++++++++++++++++++
arch/s390/kvm/pci.h | 2 ++
3 files changed, 29 insertions(+)

diff --git a/arch/s390/include/asm/kvm_pci.h b/arch/s390/include/asm/kvm_pci.h
index ed596880fb06..e27dbede723c 100644
--- a/arch/s390/include/asm/kvm_pci.h
+++ b/arch/s390/include/asm/kvm_pci.h
@@ -30,6 +30,8 @@ struct kvm_zdev {
int kvm_s390_pci_dev_open(struct zpci_dev *zdev);
void kvm_s390_pci_dev_release(struct zpci_dev *zdev);

+u8 kvm_s390_pci_get_dtsm(struct zpci_dev *zdev);
+
int zpci_iommu_attach_kvm(struct zpci_dev *zdev, struct kvm *kvm);
int zpci_iommu_kvm_assign_iota(struct zpci_dev *zdev, u64 iota);
int zpci_iommu_kvm_remove_iota(struct zpci_dev *zdev);
diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
index 2287c1c6a3e5..1a8b82220b29 100644
--- a/arch/s390/kvm/pci.c
+++ b/arch/s390/kvm/pci.c
@@ -367,6 +367,28 @@ static int kvm_s390_pci_aif_disable(struct zpci_dev *zdev, bool force)
return rc;
}

+static int kvm_s390_pci_ioat_enable(struct zpci_dev *zdev, u64 iota)
+{
+ if (IS_ENABLED(CONFIG_S390_KVM_IOMMU))
+ return zpci_iommu_kvm_assign_iota(zdev, iota);
+ else
+ return -EINVAL;
+}
+
+static int kvm_s390_pci_ioat_disable(struct zpci_dev *zdev)
+{
+ if (IS_ENABLED(CONFIG_S390_KVM_IOMMU))
+ return zpci_iommu_kvm_remove_iota(zdev);
+ else
+ return -EINVAL;
+}
+
+u8 kvm_s390_pci_get_dtsm(struct zpci_dev *zdev)
+{
+ return (zdev->dtsm & KVM_S390_PCI_DTSM_MASK);
+}
+EXPORT_SYMBOL_GPL(kvm_s390_pci_get_dtsm);
+
static int kvm_s390_pci_interp_enable(struct zpci_dev *zdev)
{
u32 gisa;
@@ -432,6 +454,9 @@ static int kvm_s390_pci_interp_disable(struct zpci_dev *zdev, bool force)
if (zdev->kzdev->fib.fmt0.aibv != 0)
kvm_s390_pci_aif_disable(zdev, force);

+ /* If we are using the IOAT assist, disable it now */
+ kvm_s390_pci_ioat_disable(zdev);
+
/* Remove the host CLP guest designation */
zdev->gisa = 0;

diff --git a/arch/s390/kvm/pci.h b/arch/s390/kvm/pci.h
index a95d9fdc91be..867f04cae3a1 100644
--- a/arch/s390/kvm/pci.h
+++ b/arch/s390/kvm/pci.h
@@ -16,6 +16,8 @@
#include <asm/airq.h>
#include <asm/kvm_pci.h>

+#define KVM_S390_PCI_DTSM_MASK 0x40
+
struct zpci_gaite {
u32 gisa;
u8 gisc;
--
2.27.0