From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: David Woodhouse <dwmw@amazon.co.uk>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>, Sasha Levin <sashal@kernel.org>,
xen-devel@lists.xenproject.org,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH AUTOSEL 5.10 24/45] xen: Fix event channel callback via INTX/GSI
Date: Tue, 19 Jan 2021 20:25:41 -0500 [thread overview]
Message-ID: <20210120012602.769683-24-sashal@kernel.org> (raw)
In-Reply-To: <20210120012602.769683-1-sashal@kernel.org>
From: David Woodhouse <dwmw@amazon.co.uk>
[ Upstream commit 3499ba8198cad47b731792e5e56b9ec2a78a83a2 ]
For a while, event channel notification via the PCI platform device
has been broken, because we attempt to communicate with xenstore before
we even have notifications working, with the xs_reset_watches() call
in xs_init().
We tend to get away with this on Xen versions below 4.0 because we avoid
calling xs_reset_watches() anyway, because xenstore might not cope with
reading a non-existent key. And newer Xen *does* have the vector
callback support, so we rarely fall back to INTX/GSI delivery.
To fix it, clean up a bit of the mess of xs_init() and xenbus_probe()
startup. Call xs_init() directly from xenbus_init() only in the !XS_HVM
case, deferring it to be called from xenbus_probe() in the XS_HVM case
instead.
Then fix up the invocation of xenbus_probe() to happen either from its
device_initcall if the callback is available early enough, or when the
callback is finally set up. This means that the hack of calling
xenbus_probe() from a workqueue after the first interrupt, or directly
from the PCI platform device setup, is no longer needed.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20210113132606.422794-2-dwmw2@infradead.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm/xen/enlighten.c | 2 +-
drivers/xen/events/events_base.c | 10 ----
drivers/xen/platform-pci.c | 1 -
drivers/xen/xenbus/xenbus.h | 1 +
drivers/xen/xenbus/xenbus_comms.c | 8 ---
drivers/xen/xenbus/xenbus_probe.c | 81 +++++++++++++++++++++++++------
include/xen/xenbus.h | 2 +-
7 files changed, 70 insertions(+), 35 deletions(-)
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 60e901cd0de6a..5a957a9a09843 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -371,7 +371,7 @@ static int __init xen_guest_init(void)
}
gnttab_init();
if (!xen_initial_domain())
- xenbus_probe(NULL);
+ xenbus_probe();
/*
* Making sure board specific code will not set up ops for
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 6038c4c35db5a..bbebe248b7264 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -2010,16 +2010,6 @@ static struct irq_chip xen_percpu_chip __read_mostly = {
.irq_ack = ack_dynirq,
};
-int xen_set_callback_via(uint64_t via)
-{
- struct xen_hvm_param a;
- a.domid = DOMID_SELF;
- a.index = HVM_PARAM_CALLBACK_IRQ;
- a.value = via;
- return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
-}
-EXPORT_SYMBOL_GPL(xen_set_callback_via);
-
#ifdef CONFIG_XEN_PVHVM
/* Vector callbacks are better than PCI interrupts to receive event
* channel notifications because we can receive vector callbacks on any
diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c
index dd911e1ff782c..9db557b76511b 100644
--- a/drivers/xen/platform-pci.c
+++ b/drivers/xen/platform-pci.c
@@ -149,7 +149,6 @@ static int platform_pci_probe(struct pci_dev *pdev,
ret = gnttab_init();
if (ret)
goto grant_out;
- xenbus_probe(NULL);
return 0;
grant_out:
gnttab_free_auto_xlat_frames();
diff --git a/drivers/xen/xenbus/xenbus.h b/drivers/xen/xenbus/xenbus.h
index 2a93b7c9c1599..dc15373354144 100644
--- a/drivers/xen/xenbus/xenbus.h
+++ b/drivers/xen/xenbus/xenbus.h
@@ -115,6 +115,7 @@ int xenbus_probe_node(struct xen_bus_type *bus,
const char *type,
const char *nodename);
int xenbus_probe_devices(struct xen_bus_type *bus);
+void xenbus_probe(void);
void xenbus_dev_changed(const char *node, struct xen_bus_type *bus);
diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c
index eb5151fc8efab..e5fda0256feb3 100644
--- a/drivers/xen/xenbus/xenbus_comms.c
+++ b/drivers/xen/xenbus/xenbus_comms.c
@@ -57,16 +57,8 @@ DEFINE_MUTEX(xs_response_mutex);
static int xenbus_irq;
static struct task_struct *xenbus_task;
-static DECLARE_WORK(probe_work, xenbus_probe);
-
-
static irqreturn_t wake_waiting(int irq, void *unused)
{
- if (unlikely(xenstored_ready == 0)) {
- xenstored_ready = 1;
- schedule_work(&probe_work);
- }
-
wake_up(&xb_waitq);
return IRQ_HANDLED;
}
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 44634d970a5ca..c8f0282bb6497 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -683,29 +683,76 @@ void unregister_xenstore_notifier(struct notifier_block *nb)
}
EXPORT_SYMBOL_GPL(unregister_xenstore_notifier);
-void xenbus_probe(struct work_struct *unused)
+void xenbus_probe(void)
{
xenstored_ready = 1;
+ /*
+ * In the HVM case, xenbus_init() deferred its call to
+ * xs_init() in case callbacks were not operational yet.
+ * So do it now.
+ */
+ if (xen_store_domain_type == XS_HVM)
+ xs_init();
+
/* Notify others that xenstore is up */
blocking_notifier_call_chain(&xenstore_chain, 0, NULL);
}
-EXPORT_SYMBOL_GPL(xenbus_probe);
-static int __init xenbus_probe_initcall(void)
+/*
+ * Returns true when XenStore init must be deferred in order to
+ * allow the PCI platform device to be initialised, before we
+ * can actually have event channel interrupts working.
+ */
+static bool xs_hvm_defer_init_for_callback(void)
{
- if (!xen_domain())
- return -ENODEV;
+#ifdef CONFIG_XEN_PVHVM
+ return xen_store_domain_type == XS_HVM &&
+ !xen_have_vector_callback;
+#else
+ return false;
+#endif
+}
- if (xen_initial_domain() || xen_hvm_domain())
- return 0;
+static int __init xenbus_probe_initcall(void)
+{
+ /*
+ * Probe XenBus here in the XS_PV case, and also XS_HVM unless we
+ * need to wait for the platform PCI device to come up.
+ */
+ if (xen_store_domain_type == XS_PV ||
+ (xen_store_domain_type == XS_HVM &&
+ !xs_hvm_defer_init_for_callback()))
+ xenbus_probe();
- xenbus_probe(NULL);
return 0;
}
-
device_initcall(xenbus_probe_initcall);
+int xen_set_callback_via(uint64_t via)
+{
+ struct xen_hvm_param a;
+ int ret;
+
+ a.domid = DOMID_SELF;
+ a.index = HVM_PARAM_CALLBACK_IRQ;
+ a.value = via;
+
+ ret = HYPERVISOR_hvm_op(HVMOP_set_param, &a);
+ if (ret)
+ return ret;
+
+ /*
+ * If xenbus_probe_initcall() deferred the xenbus_probe()
+ * due to the callback not functioning yet, we can do it now.
+ */
+ if (!xenstored_ready && xs_hvm_defer_init_for_callback())
+ xenbus_probe();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(xen_set_callback_via);
+
/* Set up event channel for xenstored which is run as a local process
* (this is normally used only in dom0)
*/
@@ -818,11 +865,17 @@ static int __init xenbus_init(void)
break;
}
- /* Initialize the interface to xenstore. */
- err = xs_init();
- if (err) {
- pr_warn("Error initializing xenstore comms: %i\n", err);
- goto out_error;
+ /*
+ * HVM domains may not have a functional callback yet. In that
+ * case let xs_init() be called from xenbus_probe(), which will
+ * get invoked at an appropriate time.
+ */
+ if (xen_store_domain_type != XS_HVM) {
+ err = xs_init();
+ if (err) {
+ pr_warn("Error initializing xenstore comms: %i\n", err);
+ goto out_error;
+ }
}
if ((xen_store_domain_type != XS_LOCAL) &&
diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
index 00c7235ae93e7..2c43b0ef1e4d5 100644
--- a/include/xen/xenbus.h
+++ b/include/xen/xenbus.h
@@ -192,7 +192,7 @@ void xs_suspend_cancel(void);
struct work_struct;
-void xenbus_probe(struct work_struct *);
+void xenbus_probe(void);
#define XENBUS_IS_ERR_READ(str) ({ \
if (!IS_ERR(str) && strlen(str) == 0) { \
--
2.27.0
next prev parent reply other threads:[~2021-01-20 2:36 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-20 1:25 [PATCH AUTOSEL 5.10 01/45] ASoC: Intel: haswell: Add missing pm_ops Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 02/45] ASoC: rt711: mutex between calibration and power state changes Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 03/45] SUNRPC: Handle TCP socket sends with kernel_sendpage() again Sasha Levin
2021-02-08 19:34 ` Trond Myklebust
2021-02-08 19:48 ` Chuck Lever
2021-02-08 20:12 ` Trond Myklebust
2021-02-08 20:17 ` Chuck Lever
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 04/45] ASoC: AMD Renoir - add DMI entry for Lenovo ThinkPad E14 Gen 2 Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 05/45] HID: multitouch: Enable multi-input for Synaptics pointstick/touchpad device Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 06/45] HID: sony: select CONFIG_CRC32 Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 07/45] dm integrity: select CRYPTO_SKCIPHER Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 08/45] x86/hyperv: Fix kexec panic/hang issues Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 09/45] scsi: ufs: Relax the condition of UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 10/45] scsi: ufs: Correct the LUN used in eh_device_reset_handler() callback Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 11/45] scsi: qedi: Correct max length of CHAP secret Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 12/45] scsi: scsi_debug: Fix memleak in scsi_debug_init() Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 13/45] scsi: sd: Suppress spurious errors when WRITE SAME is being disabled Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 14/45] riscv: Fix kernel time_init() Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 15/45] riscv: Fix sifive serial driver Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 16/45] riscv: Enable interrupts during syscalls with M-Mode Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 17/45] HID: logitech-dj: add the G602 receiver Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 18/45] HID: Ignore battery for Elan touchscreen on ASUS UX550 Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 19/45] clk: tegra30: Add hda clock default rates to clock driver Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 20/45] ALSA: hda/tegra: fix tegra-hda on tegra30 soc Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 21/45] r8152: Add Lenovo Powered USB-C Travel Hub Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 22/45] riscv: cacheinfo: Fix using smp_processor_id() in preemptible Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 23/45] arm64: make atomic helpers __always_inline Sasha Levin
2021-01-20 1:25 ` Sasha Levin [this message]
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 25/45] x86/xen: Add xen_no_vector_callback option to test PCI INTX delivery Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 26/45] x86/xen: Fix xen_hvm_smp_init() when vector callback not available Sasha Levin
2021-01-20 1:35 ` Boris Ostrovsky
2021-01-24 13:11 ` Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 27/45] net: stmmac: use __napi_schedule() for PREEMPT_RT Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 28/45] net: stmmac: Fixed mtu channged by cache aligned Sasha Levin
2021-01-20 6:08 ` Jakub Kicinski
2021-01-20 14:26 ` Sasha Levin
2021-01-21 14:39 ` [Linux-stm32] " Ahmad Fatoum
2021-01-21 16:02 ` Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 29/45] dts: phy: fix missing mdio device and probe failure of vsc8541-01 device Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 30/45] dts: phy: add GPIO number and active state used for phy reset Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 31/45] riscv: defconfig: enable gpio support for HiFive Unleashed Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 32/45] drm/amdgpu/psp: fix psp gfx ctrl cmds Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 33/45] drm/amd/display: disable dcn10 pipe split by default Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 34/45] HID: logitech-hidpp: Add product ID for MX Ergo in Bluetooth mode Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 35/45] drm/amd/display: Fix to be able to stop crc calculation Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 36/45] drm/nouveau/bios: fix issue shadowing expansion ROMs Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 37/45] drm/nouveau/privring: ack interrupts the same way as RM Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 38/45] drm/nouveau/i2c/gm200: increase width of aux semaphore owner fields Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 39/45] drm/nouveau/mmu: fix vram heap sizing Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 40/45] drm/nouveau/kms/nv50-: fix case where notifier buffer is at offset 0 Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 41/45] io_uring: flush timeouts that should already have expired Sasha Levin
2021-01-20 1:25 ` [PATCH AUTOSEL 5.10 42/45] libperf tests: If a test fails return non-zero Sasha Levin
2021-01-20 1:26 ` [PATCH AUTOSEL 5.10 43/45] libperf tests: Fail when failing to get a tracepoint id Sasha Levin
2021-01-20 1:26 ` [PATCH AUTOSEL 5.10 44/45] RISC-V: Set current memblock limit Sasha Levin
2021-01-20 1:26 ` [PATCH AUTOSEL 5.10 45/45] RISC-V: Fix maximum allowed phsyical memory for RV32 Sasha Levin
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