cxl: Support the cxl kernel API from a guest
Like on bare-metal, the cxl driver creates a virtual PHB and a pci
device for the AFU. The configuration space of the device is mapped to
the configuration record of the AFU.
Reuse the code defined in afu_cr_read8|16|32() when reading the
configuration space of the AFU device.
Even though the (virtual) AFU device is a pci device, the adapter is
not. So a driver using the cxl kernel API cannot read the VPD of the
adapter through the usual PCI interface. Therefore, we add a call to
the cxl kernel API:
ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count);
Co-authored-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/drivers/misc/cxl/guest.c b/drivers/misc/cxl/guest.c
index 816113d..2b07ebd 100644
--- a/drivers/misc/cxl/guest.c
+++ b/drivers/misc/cxl/guest.c
@@ -418,6 +418,24 @@
return _guest_afu_cr_readXX(8, afu, cr_idx, offset, out);
}
+static int guest_afu_cr_write32(struct cxl_afu *afu, int cr, u64 off, u32 in)
+{
+ /* config record is not writable from guest */
+ return -EPERM;
+}
+
+static int guest_afu_cr_write16(struct cxl_afu *afu, int cr, u64 off, u16 in)
+{
+ /* config record is not writable from guest */
+ return -EPERM;
+}
+
+static int guest_afu_cr_write8(struct cxl_afu *afu, int cr, u64 off, u8 in)
+{
+ /* config record is not writable from guest */
+ return -EPERM;
+}
+
static int attach_afu_directed(struct cxl_context *ctx, u64 wed, u64 amr)
{
struct cxl_process_element_hcall *elem;
@@ -807,6 +825,9 @@
afu->enabled = true;
+ if ((rc = cxl_pci_vphb_add(afu)))
+ dev_info(&afu->dev, "Can't register vPHB\n");
+
return 0;
err_put2:
@@ -832,6 +853,7 @@
if (!afu)
return;
+ cxl_pci_vphb_remove(afu);
cxl_sysfs_afu_remove(afu);
spin_lock(&afu->adapter->afu_list_lock);
@@ -987,4 +1009,8 @@
.afu_cr_read16 = guest_afu_cr_read16,
.afu_cr_read32 = guest_afu_cr_read32,
.afu_cr_read64 = guest_afu_cr_read64,
+ .afu_cr_write8 = guest_afu_cr_write8,
+ .afu_cr_write16 = guest_afu_cr_write16,
+ .afu_cr_write32 = guest_afu_cr_write32,
+ .read_adapter_vpd = cxl_guest_read_adapter_vpd,
};