Force specific device listed in params pm_restore_ids to follow
device state save/restore as needs_pm_restore.
Some device has NoSoftRst so will skip current state save/restore enabled
by needs_pm_restore. However once the device experienced power state
D3<->D0 transition, either by idle_d3 or the guest driver changes PM_CTL,
the guest driver won't get correct devie state although the configure
space doesn't change.

Cc: Swee Yee Fonn <swee.yee.f...@intel.com>
Signed-off-by: Colin Xu <colin...@intel.com>
---
 drivers/vfio/pci/vfio_pci.c | 66 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 65 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index e6190173482c..50a4141c9e1d 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -34,6 +34,15 @@
 #define DRIVER_AUTHOR   "Alex Williamson <alex.william...@redhat.com>"
 #define DRIVER_DESC     "VFIO PCI - User Level meta-driver"
 
+#define VFIO_MAX_PM_DEV 32
+struct vfio_pm_devs {
+       struct {
+               unsigned short  vendor;
+               unsigned short  device;
+       } ids[VFIO_MAX_PM_DEV];
+       u32 count;
+};
+
 static char ids[1024] __initdata;
 module_param_string(ids, ids, sizeof(ids), 0);
 MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the vfio driver, format is 
\"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\" and multiple 
comma separated entries can be specified");
@@ -64,6 +73,10 @@ static bool disable_denylist;
 module_param(disable_denylist, bool, 0444);
 MODULE_PARM_DESC(disable_denylist, "Disable use of device denylist. Disabling 
the denylist allows binding to devices with known errata that may lead to 
exploitable stability or security issues when accessed by untrusted users.");
 
+static char pm_restore_ids[1024] __initdata;
+module_param_string(pm_restore_ids, pm_restore_ids, sizeof(pm_restore_ids), 0);
+MODULE_PARM_DESC(pm_restore_ids, "comma separated device in format of 
\"vendor:device\"");
+
 static inline bool vfio_vga_disabled(void)
 {
 #ifdef CONFIG_VFIO_PCI_VGA
@@ -260,10 +273,50 @@ static bool vfio_pci_nointx(struct pci_dev *pdev)
        return false;
 }
 
+static struct vfio_pm_devs pm_devs = {0};
+static void __init vfio_pci_fill_pm_ids(void)
+{
+       char *p, *id;
+       int idx = 0;
+
+       /* no ids passed actually */
+       if (pm_restore_ids[0] == '\0')
+               return;
+
+       /* add ids specified in the module parameter */
+       p = pm_restore_ids;
+       while ((id = strsep(&p, ","))) {
+               unsigned int vendor, device = PCI_ANY_ID;
+               int fields;
+
+               if (!strlen(id))
+                       continue;
+
+               fields = sscanf(id, "%x:%x", &vendor, &device);
+
+               if (fields != 2) {
+                       pr_warn("invalid vendor:device string \"%s\"\n", id);
+                       continue;
+               }
+
+               if (idx < VFIO_MAX_PM_DEV) {
+                       pm_devs.ids[idx].vendor = vendor;
+                       pm_devs.ids[idx].device = device;
+                       pm_devs.count++;
+                       idx++;
+                       pr_info("add [%04x:%04x] for needs_pm_restore\n",
+                               vendor, device);
+               } else {
+                       pr_warn("Exceed maximum %d, skip adding [%04x:%04x] for 
needs_pm_restore\n",
+                               VFIO_MAX_PM_DEV, vendor, device);
+               }
+       }
+}
+
 static void vfio_pci_probe_power_state(struct vfio_pci_device *vdev)
 {
        struct pci_dev *pdev = vdev->pdev;
-       u16 pmcsr;
+       u16 pmcsr, idx;
 
        if (!pdev->pm_cap)
                return;
@@ -271,6 +324,16 @@ static void vfio_pci_probe_power_state(struct 
vfio_pci_device *vdev)
        pci_read_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, &pmcsr);
 
        vdev->needs_pm_restore = !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET);
+
+       for (idx = 0; idx < pm_devs.count; idx++) {
+               if (vdev->pdev->vendor == pm_devs.ids[idx].vendor &&
+                   vdev->pdev->device == pm_devs.ids[idx].device) {
+                       vdev->needs_pm_restore = true;
+                       pr_info("force [%04x:%04x] to needs_pm_restore\n",
+                               vdev->pdev->vendor, vdev->pdev->device);
+                       break;
+               }
+       }
 }
 
 /*
@@ -2423,6 +2486,7 @@ static int __init vfio_pci_init(void)
                goto out_driver;
 
        vfio_pci_fill_ids();
+       vfio_pci_fill_pm_ids();
 
        if (disable_denylist)
                pr_warn("device denylist disabled.\n");
-- 
2.29.2

Reply via email to