From 41608b64b10b80fe00dd253cd8326ec8ad85930f Mon Sep 17 00:00:00 2001
From: Long Li <longli@microsoft.com>
Date: Mon, 30 Aug 2021 16:13:27 -0700
Subject: [PATCH 1/3] PCI: hv: Fix sleep while in non-sleep context when
removing child devices from the bus
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In hv_pci_bus_exit, the code is holding a spinlock while calling
pci_destroy_slot(), which takes a mutex.
This is not safe for spinlock. Fix this by moving the children to be
deleted to a list on the stack, and removing them after spinlock is
released.
Fixes: 94d22763207a ("PCI: hv: Fix a race condition when removing the device")
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: "Krzysztof Wilczyński" <kw@linux.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Michael Kelley <mikelley@microsoft.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/linux-hyperv/20210823152130.GA21501@kili/
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/1630365207-20616-1-git-send-email-longli@linuxonhyperv.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
drivers/pci/controller/pci-hyperv.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index a53bd8728d0d..fc1a29acadbb 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -3229,9 +3229,17 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
return 0;
if (!keep_devs) {
- /* Delete any children which might still exist. */
+ struct list_head removed;
+
+ /* Move all present children to the list on stack */
+ INIT_LIST_HEAD(&removed);
spin_lock_irqsave(&hbus->device_list_lock, flags);
- list_for_each_entry_safe(hpdev, tmp, &hbus->children, list_entry) {
+ list_for_each_entry_safe(hpdev, tmp, &hbus->children, list_entry)
+ list_move_tail(&hpdev->list_entry, &removed);
+ spin_unlock_irqrestore(&hbus->device_list_lock, flags);
+
+ /* Remove all children in the list */
+ list_for_each_entry_safe(hpdev, tmp, &removed, list_entry) {
list_del(&hpdev->list_entry);
if (hpdev->pci_slot)
pci_destroy_slot(hpdev->pci_slot);
@@ -3239,7 +3247,6 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
put_pcichild(hpdev);
put_pcichild(hpdev);
}
- spin_unlock_irqrestore(&hbus->device_list_lock, flags);
}
ret = hv_send_resources_released(hdev);
From 95a13ee858c9e426e63c97063677736f74af7163 Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Fri, 1 Oct 2021 16:55:44 +0300
Subject: [PATCH 2/3] hyper-v: Replace uuid.h with types.h
There is no user of anything in uuid.h in the hyperv.h. Replace it with
more appropriate types.h.
Fixes: f081bbb3fd03 ("hyper-v: Remove internal types from UAPI header")
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Link: https://lore.kernel.org/r/20211001135544.1823-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
include/uapi/linux/hyperv.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/uapi/linux/hyperv.h b/include/uapi/linux/hyperv.h
index 6135d92e0d47..daf82a230c0e 100644
--- a/include/uapi/linux/hyperv.h
+++ b/include/uapi/linux/hyperv.h
@@ -26,7 +26,7 @@
#ifndef _UAPI_HYPERV_H
#define _UAPI_HYPERV_H
-#include <linux/uuid.h>
+#include <linux/types.h>
/*
* Framework version for util services.
From f5c20e4a5f18677e22d8dd2846066251b006a62d Mon Sep 17 00:00:00 2001
From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: Wed, 6 Oct 2021 14:50:16 +0200
Subject: [PATCH 3/3] x86/hyperv: Avoid erroneously sending IPI to 'self'
__send_ipi_mask_ex() uses an optimization: when the target CPU mask is
equal to 'cpu_present_mask' it uses 'HV_GENERIC_SET_ALL' format to avoid
converting the specified cpumask to VP_SET. This case was overlooked when
'exclude_self' parameter was added. As the result, a spurious IPI to
'self' can be send.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Fixes: dfb5c1e12c28 ("x86/hyperv: remove on-stack cpumask from hv_send_ipi_mask_allbutself")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20211006125016.941616-1-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
arch/x86/hyperv/hv_apic.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index 32a1ad356c18..db2d92fb44da 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -122,17 +122,27 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector,
ipi_arg->reserved = 0;
ipi_arg->vp_set.valid_bank_mask = 0;
- if (!cpumask_equal(mask, cpu_present_mask)) {
+ /*
+ * Use HV_GENERIC_SET_ALL and avoid converting cpumask to VP_SET
+ * when the IPI is sent to all currently present CPUs.
+ */
+ if (!cpumask_equal(mask, cpu_present_mask) || exclude_self) {
ipi_arg->vp_set.format = HV_GENERIC_SET_SPARSE_4K;
if (exclude_self)
nr_bank = cpumask_to_vpset_noself(&(ipi_arg->vp_set), mask);
else
nr_bank = cpumask_to_vpset(&(ipi_arg->vp_set), mask);
- }
- if (nr_bank < 0)
- goto ipi_mask_ex_done;
- if (!nr_bank)
+
+ /*
+ * 'nr_bank <= 0' means some CPUs in cpumask can't be
+ * represented in VP_SET. Return an error and fall back to
+ * native (architectural) method of sending IPIs.
+ */
+ if (nr_bank <= 0)
+ goto ipi_mask_ex_done;
+ } else {
ipi_arg->vp_set.format = HV_GENERIC_SET_ALL;
+ }
status = hv_do_rep_hypercall(HVCALL_SEND_IPI_EX, 0, nr_bank,
ipi_arg, NULL);