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authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-19 09:38:27 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-19 09:38:27 -0800
commit086675779097c6fe95e94058072462196ffd1870 (patch)
tree89e0ed9e564beb7df7a99ade529b164c034d87a8
parentfb1d8e0e2c50f374cfc244564decfc3f0a336cb4 (diff)
parentda72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1 (diff)
downloadlinux-086675779097c6fe95e94058072462196ffd1870.tar.bz2
Merge tag 'for-linus-4.10-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fix from Juergen Gross: "A fix for Xen running in nested virtualization environment" * tag 'for-linus-4.10-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: partially revert "xen: Remove event channel notification through Xen PCI platform device"
-rw-r--r--drivers/xen/platform-pci.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c
index 112ce422dc22..2a165cc8a43c 100644
--- a/drivers/xen/platform-pci.c
+++ b/drivers/xen/platform-pci.c
@@ -42,6 +42,7 @@
static unsigned long platform_mmio;
static unsigned long platform_mmio_alloc;
static unsigned long platform_mmiolen;
+static uint64_t callback_via;
static unsigned long alloc_xen_mmio(unsigned long len)
{
@@ -54,6 +55,51 @@ static unsigned long alloc_xen_mmio(unsigned long len)
return addr;
}
+static uint64_t get_callback_via(struct pci_dev *pdev)
+{
+ u8 pin;
+ int irq;
+
+ irq = pdev->irq;
+ if (irq < 16)
+ return irq; /* ISA IRQ */
+
+ pin = pdev->pin;
+
+ /* We don't know the GSI. Specify the PCI INTx line instead. */
+ return ((uint64_t)0x01 << HVM_CALLBACK_VIA_TYPE_SHIFT) | /* PCI INTx identifier */
+ ((uint64_t)pci_domain_nr(pdev->bus) << 32) |
+ ((uint64_t)pdev->bus->number << 16) |
+ ((uint64_t)(pdev->devfn & 0xff) << 8) |
+ ((uint64_t)(pin - 1) & 3);
+}
+
+static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
+{
+ xen_hvm_evtchn_do_upcall();
+ return IRQ_HANDLED;
+}
+
+static int xen_allocate_irq(struct pci_dev *pdev)
+{
+ return request_irq(pdev->irq, do_hvm_evtchn_intr,
+ IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
+ "xen-platform-pci", pdev);
+}
+
+static int platform_pci_resume(struct pci_dev *pdev)
+{
+ int err;
+ if (!xen_pv_domain())
+ return 0;
+ err = xen_set_callback_via(callback_via);
+ if (err) {
+ dev_err(&pdev->dev, "platform_pci_resume failure!\n");
+ return err;
+ }
+ return 0;
+}
+
static int platform_pci_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
@@ -92,6 +138,28 @@ static int platform_pci_probe(struct pci_dev *pdev,
platform_mmio = mmio_addr;
platform_mmiolen = mmio_len;
+ /*
+ * Xen HVM guests always use the vector callback mechanism.
+ * L1 Dom0 in a nested Xen environment is a PV guest inside in an
+ * HVM environment. It needs the platform-pci driver to get
+ * notifications from L0 Xen, but it cannot use the vector callback
+ * as it is not exported by L1 Xen.
+ */
+ if (xen_pv_domain()) {
+ ret = xen_allocate_irq(pdev);
+ if (ret) {
+ dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
+ goto out;
+ }
+ callback_via = get_callback_via(pdev);
+ ret = xen_set_callback_via(callback_via);
+ if (ret) {
+ dev_warn(&pdev->dev, "Unable to set the evtchn callback "
+ "err=%d\n", ret);
+ goto out;
+ }
+ }
+
max_nr_gframes = gnttab_max_grant_frames();
grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
ret = gnttab_setup_auto_xlat_frames(grant_frames);
@@ -123,6 +191,9 @@ static struct pci_driver platform_driver = {
.name = DRV_NAME,
.probe = platform_pci_probe,
.id_table = platform_pci_tbl,
+#ifdef CONFIG_PM
+ .resume_early = platform_pci_resume,
+#endif
};
builtin_pci_driver(platform_driver);