From: Colin Xu <colin.xu@intel.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: colin.xu@intel.com, swee.yee.fonn@intel.com
Subject: [RFC PATCH] vfio/pci: Allow force needs_pm_restore as specified by device:vendor
Date: Wed, 25 Nov 2020 10:18:24 +0800 [thread overview]
Message-ID: <20201125021824.27411-1-colin.xu@intel.com> (raw)
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.fonn@intel.com>
Signed-off-by: Colin Xu <colin.xu@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.williamson@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
next reply other threads:[~2020-11-25 2:18 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-25 2:18 Colin Xu [this message]
2020-11-25 15:53 ` [RFC PATCH] vfio/pci: Allow force needs_pm_restore as specified by device:vendor Alex Williamson
2020-11-27 3:53 ` Colin Xu
2020-11-27 15:35 ` Alex Williamson
2020-12-09 5:14 ` Colin Xu
2020-12-09 17:09 ` Alex Williamson
2020-12-15 1:16 ` Colin Xu
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