* [PATCH 2/7] PCI/PM: Correct pci_pm_thaw_noirq() documentation
From: Bjorn Helgaas @ 2019-10-14 23:00 UTC (permalink / raw)
To: Dexuan Cui
Cc: Rafael J . Wysocki, Lorenzo Pieralisi, Michael Kelley,
Sasha Levin, Haiyang Zhang, KY Srinivasan, Stephen Hemminger,
olaf, apw, jasowang, vkuznets, marcelo.cerri, jackm, linux-pci,
linux-hyperv, linux-kernel, driverdev-devel, Bjorn Helgaas
In-Reply-To: <20191014230016.240912-1-helgaas@kernel.org>
From: Bjorn Helgaas <bhelgaas@google.com>
According to the documentation, pci_pm_thaw_noirq() did not put the device
into the full-power state and restore its standard configuration registers.
This is incorrect, so update the documentation to match the code.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
Documentation/power/pci.rst | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/Documentation/power/pci.rst b/Documentation/power/pci.rst
index 0e2ef7429304..1525c594d631 100644
--- a/Documentation/power/pci.rst
+++ b/Documentation/power/pci.rst
@@ -600,17 +600,17 @@ using the following PCI bus type's callbacks::
respectively.
-The first of them, pci_pm_thaw_noirq(), is analogous to pci_pm_resume_noirq(),
-but it doesn't put the device into the full power state and doesn't attempt to
-restore its standard configuration registers. It also executes the device
-driver's pm->thaw_noirq() callback, if defined, instead of pm->resume_noirq().
+The first of them, pci_pm_thaw_noirq(), is analogous to pci_pm_resume_noirq().
+It puts the device into the full power state and restores its standard
+configuration registers. It also executes the device driver's pm->thaw_noirq()
+callback, if defined, instead of pm->resume_noirq().
The pci_pm_thaw() routine is similar to pci_pm_resume(), but it runs the device
driver's pm->thaw() callback instead of pm->resume(). It is executed
asynchronously for different PCI devices that don't depend on each other in a
known way.
-The complete phase it the same as for system resume.
+The complete phase is the same as for system resume.
After saving the image, devices need to be powered down before the system can
enter the target sleep state (ACPI S4 for ACPI-based systems). This is done in
--
2.23.0.700.g56cf767bdb-goog
^ permalink raw reply related
* [PATCH 3/7] PCI/PM: Clear PCIe PME Status even for legacy power management
From: Bjorn Helgaas @ 2019-10-14 23:00 UTC (permalink / raw)
To: Dexuan Cui
Cc: Rafael J . Wysocki, Lorenzo Pieralisi, Michael Kelley,
Sasha Levin, Haiyang Zhang, KY Srinivasan, Stephen Hemminger,
olaf, apw, jasowang, vkuznets, marcelo.cerri, jackm, linux-pci,
linux-hyperv, linux-kernel, driverdev-devel, Bjorn Helgaas
In-Reply-To: <20191014230016.240912-1-helgaas@kernel.org>
From: Bjorn Helgaas <bhelgaas@google.com>
Previously, pci_pm_resume_noirq() cleared the PME Status bit in the Root
Status register only if the device had no driver or the driver did not
implement legacy power management. It should clear PME Status regardless
of what sort of power management the driver supports, so do this before
checking for legacy power management.
This affects Root Ports and Root Complex Event Collectors, for which the
usual driver is the PCIe portdrv, which implements new power management, so
this change is just on principle, not to fix any actual defects.
Fixes: a39bd851dccf ("PCI/PM: Clear PCIe PME Status bit in core, not PCIe port driver")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/pci-driver.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index d4ac8ce8c1f9..0c3086793e4e 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -941,12 +941,11 @@ static int pci_pm_resume_noirq(struct device *dev)
pci_pm_default_resume_early(pci_dev);
pci_fixup_device(pci_fixup_resume_early, pci_dev);
+ pcie_pme_root_status_cleanup(pci_dev);
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_resume_early(dev);
- pcie_pme_root_status_cleanup(pci_dev);
-
if (drv && drv->pm && drv->pm->resume_noirq)
error = drv->pm->resume_noirq(dev);
--
2.23.0.700.g56cf767bdb-goog
^ permalink raw reply related
* [PATCH 4/7] PCI/PM: Run resume fixups before disabling wakeup events
From: Bjorn Helgaas @ 2019-10-14 23:00 UTC (permalink / raw)
To: Dexuan Cui
Cc: Rafael J . Wysocki, Lorenzo Pieralisi, Michael Kelley,
Sasha Levin, Haiyang Zhang, KY Srinivasan, Stephen Hemminger,
olaf, apw, jasowang, vkuznets, marcelo.cerri, jackm, linux-pci,
linux-hyperv, linux-kernel, driverdev-devel, Bjorn Helgaas
In-Reply-To: <20191014230016.240912-1-helgaas@kernel.org>
From: Bjorn Helgaas <bhelgaas@google.com>
pci_pm_resume() and pci_pm_restore() call pci_pm_default_resume(), which
runs resume fixups before disabling wakeup events:
static void pci_pm_default_resume(struct pci_dev *pci_dev)
{
pci_fixup_device(pci_fixup_resume, pci_dev);
pci_enable_wake(pci_dev, PCI_D0, false);
}
pci_pm_runtime_resume() does both of these, but in the opposite order:
pci_enable_wake(pci_dev, PCI_D0, false);
pci_fixup_device(pci_fixup_resume, pci_dev);
We should always use the same ordering unless there's a reason to do
otherwise. Change pci_pm_runtime_resume() to call pci_pm_default_resume()
instead of open-coding this, so the fixups are always done before disabling
wakeup events.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/pci-driver.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 0c3086793e4e..55acb658273f 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -1345,8 +1345,7 @@ static int pci_pm_runtime_resume(struct device *dev)
return 0;
pci_fixup_device(pci_fixup_resume_early, pci_dev);
- pci_enable_wake(pci_dev, PCI_D0, false);
- pci_fixup_device(pci_fixup_resume, pci_dev);
+ pci_pm_default_resume(pci_dev);
if (pm && pm->runtime_resume)
rc = pm->runtime_resume(dev);
--
2.23.0.700.g56cf767bdb-goog
^ permalink raw reply related
* [PATCH 7/7] PCI/MSI: Move power state check out of pci_msi_supported()
From: Bjorn Helgaas @ 2019-10-14 23:00 UTC (permalink / raw)
To: Dexuan Cui
Cc: Rafael J . Wysocki, Lorenzo Pieralisi, Michael Kelley,
Sasha Levin, Haiyang Zhang, KY Srinivasan, Stephen Hemminger,
olaf, apw, jasowang, vkuznets, marcelo.cerri, jackm, linux-pci,
linux-hyperv, linux-kernel, driverdev-devel, Bjorn Helgaas
In-Reply-To: <20191014230016.240912-1-helgaas@kernel.org>
From: Bjorn Helgaas <bhelgaas@google.com>
27e20603c54b ("PCI/MSI: Move D0 check into pci_msi_check_device()")
moved the power state check into pci_msi_check_device(), which was
subsequently renamed to pci_msi_supported(). This didn't change the
behavior, since both callers checked the power state.
However, it doesn't fit the current "pci_msi_supported()" name, which
should return what the device is capable of, independent of the power
state.
Move the power state check back into the callers for readability. No
functional change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/msi.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 0884bedcfc7a..20e9c729617c 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -861,7 +861,7 @@ static int pci_msi_supported(struct pci_dev *dev, int nvec)
if (!pci_msi_enable)
return 0;
- if (!dev || dev->no_msi || dev->current_state != PCI_D0)
+ if (!dev || dev->no_msi)
return 0;
/*
@@ -972,7 +972,7 @@ static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
int nr_entries;
int i, j;
- if (!pci_msi_supported(dev, nvec))
+ if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
return -EINVAL;
nr_entries = pci_msix_vec_count(dev);
@@ -1058,7 +1058,7 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
int nvec;
int rc;
- if (!pci_msi_supported(dev, minvec))
+ if (!pci_msi_supported(dev, minvec) || dev->current_state != PCI_D0)
return -EINVAL;
/* Check whether driver already requested MSI-X IRQs */
--
2.23.0.700.g56cf767bdb-goog
^ permalink raw reply related
* [PATCH 6/7] PCI/PM: Wrap long lines in documentation
From: Bjorn Helgaas @ 2019-10-14 23:00 UTC (permalink / raw)
To: Dexuan Cui
Cc: Rafael J . Wysocki, Lorenzo Pieralisi, Michael Kelley,
Sasha Levin, Haiyang Zhang, KY Srinivasan, Stephen Hemminger,
olaf, apw, jasowang, vkuznets, marcelo.cerri, jackm, linux-pci,
linux-hyperv, linux-kernel, driverdev-devel, Bjorn Helgaas
In-Reply-To: <20191014230016.240912-1-helgaas@kernel.org>
From: Bjorn Helgaas <bhelgaas@google.com>
Documentation/power/pci.rst is wrapped to fit in 80 columns, but directory
structure changes made a few lines longer. Wrap them so they all fit in 80
columns again.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
Documentation/power/pci.rst | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/Documentation/power/pci.rst b/Documentation/power/pci.rst
index 1525c594d631..db41a770a2f5 100644
--- a/Documentation/power/pci.rst
+++ b/Documentation/power/pci.rst
@@ -426,12 +426,12 @@ pm->runtime_idle() callback.
2.4. System-Wide Power Transitions
----------------------------------
There are a few different types of system-wide power transitions, described in
-Documentation/driver-api/pm/devices.rst. Each of them requires devices to be handled
-in a specific way and the PM core executes subsystem-level power management
-callbacks for this purpose. They are executed in phases such that each phase
-involves executing the same subsystem-level callback for every device belonging
-to the given subsystem before the next phase begins. These phases always run
-after tasks have been frozen.
+Documentation/driver-api/pm/devices.rst. Each of them requires devices to be
+handled in a specific way and the PM core executes subsystem-level power
+management callbacks for this purpose. They are executed in phases such that
+each phase involves executing the same subsystem-level callback for every device
+belonging to the given subsystem before the next phase begins. These phases
+always run after tasks have been frozen.
2.4.1. System Suspend
^^^^^^^^^^^^^^^^^^^^^
@@ -636,12 +636,12 @@ System restore requires a hibernation image to be loaded into memory and the
pre-hibernation memory contents to be restored before the pre-hibernation system
activity can be resumed.
-As described in Documentation/driver-api/pm/devices.rst, the hibernation image is loaded
-into memory by a fresh instance of the kernel, called the boot kernel, which in
-turn is loaded and run by a boot loader in the usual way. After the boot kernel
-has loaded the image, it needs to replace its own code and data with the code
-and data of the "hibernated" kernel stored within the image, called the image
-kernel. For this purpose all devices are frozen just like before creating
+As described in Documentation/driver-api/pm/devices.rst, the hibernation image
+is loaded into memory by a fresh instance of the kernel, called the boot kernel,
+which in turn is loaded and run by a boot loader in the usual way. After the
+boot kernel has loaded the image, it needs to replace its own code and data with
+the code and data of the "hibernated" kernel stored within the image, called the
+image kernel. For this purpose all devices are frozen just like before creating
the image during hibernation, in the
prepare, freeze, freeze_noirq
@@ -691,8 +691,8 @@ controlling the runtime power management of their devices.
At the time of this writing there are two ways to define power management
callbacks for a PCI device driver, the recommended one, based on using a
-dev_pm_ops structure described in Documentation/driver-api/pm/devices.rst, and the
-"legacy" one, in which the .suspend(), .suspend_late(), .resume_early(), and
+dev_pm_ops structure described in Documentation/driver-api/pm/devices.rst, and
+the "legacy" one, in which the .suspend(), .suspend_late(), .resume_early(), and
.resume() callbacks from struct pci_driver are used. The legacy approach,
however, doesn't allow one to define runtime power management callbacks and is
not really suitable for any new drivers. Therefore it is not covered by this
--
2.23.0.700.g56cf767bdb-goog
^ permalink raw reply related
* [PATCH 5/7] PCI/PM: Make power management op coding style consistent
From: Bjorn Helgaas @ 2019-10-14 23:00 UTC (permalink / raw)
To: Dexuan Cui
Cc: Rafael J . Wysocki, Lorenzo Pieralisi, Michael Kelley,
Sasha Levin, Haiyang Zhang, KY Srinivasan, Stephen Hemminger,
olaf, apw, jasowang, vkuznets, marcelo.cerri, jackm, linux-pci,
linux-hyperv, linux-kernel, driverdev-devel, Bjorn Helgaas
In-Reply-To: <20191014230016.240912-1-helgaas@kernel.org>
From: Bjorn Helgaas <bhelgaas@google.com>
Some of the power management ops use this style:
struct device_driver *drv = dev->driver;
if (drv && drv->pm && drv->pm->prepare(dev))
drv->pm->prepare(dev);
while others use this:
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (pm && pm->runtime_resume)
pm->runtime_resume(dev);
Convert the first style to the second so they're all consistent. Remove
local "error" variables when unnecessary. No functional change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/pci-driver.c | 76 +++++++++++++++++++---------------------
1 file changed, 36 insertions(+), 40 deletions(-)
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 55acb658273f..abbf5c39cb9c 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -679,11 +679,11 @@ static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev)
static int pci_pm_prepare(struct device *dev)
{
- struct device_driver *drv = dev->driver;
struct pci_dev *pci_dev = to_pci_dev(dev);
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
- if (drv && drv->pm && drv->pm->prepare) {
- int error = drv->pm->prepare(dev);
+ if (pm && pm->prepare) {
+ int error = pm->prepare(dev);
if (error < 0)
return error;
@@ -917,8 +917,7 @@ static int pci_pm_suspend_noirq(struct device *dev)
static int pci_pm_resume_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
- struct device_driver *drv = dev->driver;
- int error = 0;
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (dev_pm_may_skip_resume(dev))
return 0;
@@ -946,17 +945,16 @@ static int pci_pm_resume_noirq(struct device *dev)
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_resume_early(dev);
- if (drv && drv->pm && drv->pm->resume_noirq)
- error = drv->pm->resume_noirq(dev);
+ if (pm && pm->resume_noirq)
+ return pm->resume_noirq(dev);
- return error;
+ return 0;
}
static int pci_pm_resume(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
- int error = 0;
/*
* This is necessary for the suspend error path in which resume is
@@ -972,12 +970,12 @@ static int pci_pm_resume(struct device *dev)
if (pm) {
if (pm->resume)
- error = pm->resume(dev);
+ return pm->resume(dev);
} else {
pci_pm_reenable_device(pci_dev);
}
- return error;
+ return 0;
}
#else /* !CONFIG_SUSPEND */
@@ -1038,16 +1036,16 @@ static int pci_pm_freeze(struct device *dev)
static int pci_pm_freeze_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
- struct device_driver *drv = dev->driver;
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_suspend_late(dev, PMSG_FREEZE);
- if (drv && drv->pm && drv->pm->freeze_noirq) {
+ if (pm && pm->freeze_noirq) {
int error;
- error = drv->pm->freeze_noirq(dev);
- suspend_report_result(drv->pm->freeze_noirq, error);
+ error = pm->freeze_noirq(dev);
+ suspend_report_result(pm->freeze_noirq, error);
if (error)
return error;
}
@@ -1066,8 +1064,8 @@ static int pci_pm_freeze_noirq(struct device *dev)
static int pci_pm_thaw_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
- struct device_driver *drv = dev->driver;
- int error = 0;
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+ int error;
if (pcibios_pm_ops.thaw_noirq) {
error = pcibios_pm_ops.thaw_noirq(dev);
@@ -1091,10 +1089,10 @@ static int pci_pm_thaw_noirq(struct device *dev)
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_resume_early(dev);
- if (drv && drv->pm && drv->pm->thaw_noirq)
- error = drv->pm->thaw_noirq(dev);
+ if (pm && pm->thaw_noirq)
+ return pm->thaw_noirq(dev);
- return error;
+ return 0;
}
static int pci_pm_thaw(struct device *dev)
@@ -1165,24 +1163,24 @@ static int pci_pm_poweroff_late(struct device *dev)
static int pci_pm_poweroff_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
- struct device_driver *drv = dev->driver;
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (dev_pm_smart_suspend_and_suspended(dev))
return 0;
- if (pci_has_legacy_pm_support(to_pci_dev(dev)))
+ if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_suspend_late(dev, PMSG_HIBERNATE);
- if (!drv || !drv->pm) {
+ if (!pm) {
pci_fixup_device(pci_fixup_suspend_late, pci_dev);
return 0;
}
- if (drv->pm->poweroff_noirq) {
+ if (pm->poweroff_noirq) {
int error;
- error = drv->pm->poweroff_noirq(dev);
- suspend_report_result(drv->pm->poweroff_noirq, error);
+ error = pm->poweroff_noirq(dev);
+ suspend_report_result(pm->poweroff_noirq, error);
if (error)
return error;
}
@@ -1208,8 +1206,8 @@ static int pci_pm_poweroff_noirq(struct device *dev)
static int pci_pm_restore_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
- struct device_driver *drv = dev->driver;
- int error = 0;
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+ int error;
if (pcibios_pm_ops.restore_noirq) {
error = pcibios_pm_ops.restore_noirq(dev);
@@ -1223,17 +1221,16 @@ static int pci_pm_restore_noirq(struct device *dev)
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_resume_early(dev);
- if (drv && drv->pm && drv->pm->restore_noirq)
- error = drv->pm->restore_noirq(dev);
+ if (pm && pm->restore_noirq)
+ return pm->restore_noirq(dev);
- return error;
+ return 0;
}
static int pci_pm_restore(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
- int error = 0;
/*
* This is necessary for the hibernation error path in which restore is
@@ -1249,12 +1246,12 @@ static int pci_pm_restore(struct device *dev)
if (pm) {
if (pm->restore)
- error = pm->restore(dev);
+ return pm->restore(dev);
} else {
pci_pm_reenable_device(pci_dev);
}
- return error;
+ return 0;
}
#else /* !CONFIG_HIBERNATE_CALLBACKS */
@@ -1330,9 +1327,9 @@ static int pci_pm_runtime_suspend(struct device *dev)
static int pci_pm_runtime_resume(struct device *dev)
{
- int rc = 0;
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+ int error = 0;
/*
* Restoring config space is necessary even if the device is not bound
@@ -1348,18 +1345,17 @@ static int pci_pm_runtime_resume(struct device *dev)
pci_pm_default_resume(pci_dev);
if (pm && pm->runtime_resume)
- rc = pm->runtime_resume(dev);
+ error = pm->runtime_resume(dev);
pci_dev->runtime_d3cold = false;
- return rc;
+ return error;
}
static int pci_pm_runtime_idle(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
- int ret = 0;
/*
* If pci_dev->driver is not set (unbound), the device should
@@ -1372,9 +1368,9 @@ static int pci_pm_runtime_idle(struct device *dev)
return -ENOSYS;
if (pm->runtime_idle)
- ret = pm->runtime_idle(dev);
+ return pm->runtime_idle(dev);
- return ret;
+ return 0;
}
static const struct dev_pm_ops pci_dev_pm_ops = {
--
2.23.0.700.g56cf767bdb-goog
^ permalink raw reply related
* [PATCH v6 0/5] Add a unified parameter "nopvspin"
From: Zhenzhong Duan @ 2019-10-15 1:19 UTC (permalink / raw)
To: linux-kernel
Cc: vkuznets, linux-hyperv, kvm, kys, haiyangz, sthemmin, sashal,
tglx, mingo, bp, pbonzini, rkrcmar, sean.j.christopherson,
wanpengli, jmattson, joro, boris.ostrovsky, jgross, sstabellini,
peterz, Zhenzhong Duan
There are cases folks want to disable spinlock optimization for
debug/test purpose. Xen and hyperv already have parameters "xen_nopvspin"
and "hv_nopvspin" to support that, but kvm doesn't.
The first patch adds that feature to KVM guest with "nopvspin".
For compatibility reason original parameters "xen_nopvspin" and
"hv_nopvspin" are retained and marked obsolete.
v6:
PATCH1: add Reviewed-by [Vitaly Kuznetsov]
PATCH2: change 'pv' to 'PV', add Reviewed-by [Vitaly Kuznetsov]
PATCH3: refactor 'if' branch in kvm_spinlock_init() [Vitaly Kuznetsov]
v5:
PATCH1: new patch to revert a currently unnecessory commit,
code is simpler a bit after that change. [Boris Ostrovsky]
PATCH3: fold 'if' statement,add comments on virt_spin_lock_key,
reorder with PATCH2 to better reflect dependency
PATCH4: fold 'if' statement, add Reviewed-by [Boris Ostrovsky]
PATCH5: add Reviewed-by [Michael Kelley]
v4:
PATCH1: use variable name nopvspin instead of pvspin and
defined it as __initdata, changed print message,
updated patch description [Sean Christopherson]
PATCH2: remove Suggested-by, use "kvm-guest:" prefix [Sean Christopherson]
PATCH3: make variable nopvsin and xen_pvspin coexist
remove Reviewed-by due to code change [Sean Christopherson]
PATCH4: make variable nopvsin and hv_pvspin coexist [Sean Christopherson]
v3:
PATCH2: Fix indentation
v2:
PATCH1: pick the print code change into separate PATCH2,
updated patch description [Vitaly Kuznetsov]
PATCH2: new patch with print code change [Vitaly Kuznetsov]
PATCH3: add Reviewed-by [Juergen Gross]
Zhenzhong Duan (5):
Revert "KVM: X86: Fix setup the virt_spin_lock_key before static key
get initialized"
x86/kvm: Change print code to use pr_*() format
x86/kvm: Add "nopvspin" parameter to disable PV spinlocks
xen: Mark "xen_nopvspin" parameter obsolete
x86/hyperv: Mark "hv_nopvspin" parameter obsolete
Documentation/admin-guide/kernel-parameters.txt | 14 ++++-
arch/x86/hyperv/hv_spinlock.c | 4 ++
arch/x86/include/asm/qspinlock.h | 1 +
arch/x86/kernel/kvm.c | 76 ++++++++++++++++---------
arch/x86/xen/spinlock.c | 4 +-
kernel/locking/qspinlock.c | 7 +++
6 files changed, 75 insertions(+), 31 deletions(-)
--
1.8.3.1
^ permalink raw reply
* [PATCH v6 2/5] x86/kvm: Change print code to use pr_*() format
From: Zhenzhong Duan @ 2019-10-15 1:19 UTC (permalink / raw)
To: linux-kernel
Cc: vkuznets, linux-hyperv, kvm, kys, haiyangz, sthemmin, sashal,
tglx, mingo, bp, pbonzini, rkrcmar, sean.j.christopherson,
wanpengli, jmattson, joro, boris.ostrovsky, jgross, sstabellini,
peterz, Zhenzhong Duan, H. Peter Anvin
In-Reply-To: <1571102367-31595-1-git-send-email-zhenzhong.duan@oracle.com>
pr_*() is preferred than printk(KERN_* ...), after change all the print
in arch/x86/kernel/kvm.c will have "kvm_guest: xxx" style.
No functional change.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
arch/x86/kernel/kvm.c | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 3bc6a266..249f14a 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -7,6 +7,8 @@
* Authors: Anthony Liguori <aliguori@us.ibm.com>
*/
+#define pr_fmt(fmt) "kvm_guest: " fmt
+
#include <linux/context_tracking.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -286,8 +288,8 @@ static void kvm_register_steal_time(void)
return;
wrmsrl(MSR_KVM_STEAL_TIME, (slow_virt_to_phys(st) | KVM_MSR_ENABLED));
- pr_info("kvm-stealtime: cpu %d, msr %llx\n",
- cpu, (unsigned long long) slow_virt_to_phys(st));
+ pr_info("stealtime: cpu %d, msr %llx\n", cpu,
+ (unsigned long long) slow_virt_to_phys(st));
}
static DEFINE_PER_CPU_DECRYPTED(unsigned long, kvm_apic_eoi) = KVM_PV_EOI_DISABLED;
@@ -321,8 +323,7 @@ static void kvm_guest_cpu_init(void)
wrmsrl(MSR_KVM_ASYNC_PF_EN, pa);
__this_cpu_write(apf_reason.enabled, 1);
- printk(KERN_INFO"KVM setup async PF for cpu %d\n",
- smp_processor_id());
+ pr_info("setup async PF for cpu %d\n", smp_processor_id());
}
if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) {
@@ -347,8 +348,7 @@ static void kvm_pv_disable_apf(void)
wrmsrl(MSR_KVM_ASYNC_PF_EN, 0);
__this_cpu_write(apf_reason.enabled, 0);
- printk(KERN_INFO"Unregister pv shared memory for cpu %d\n",
- smp_processor_id());
+ pr_info("Unregister PV shared memory for cpu %d\n", smp_processor_id());
}
static void kvm_pv_guest_cpu_reboot(void *unused)
@@ -469,7 +469,8 @@ static void __send_ipi_mask(const struct cpumask *mask, int vector)
} else {
ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
(unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr);
- WARN_ONCE(ret < 0, "KVM: failed to send PV IPI: %ld", ret);
+ WARN_ONCE(ret < 0, "kvm_guest: failed to send PV IPI: %ld",
+ ret);
min = max = apic_id;
ipi_bitmap = 0;
}
@@ -479,7 +480,8 @@ static void __send_ipi_mask(const struct cpumask *mask, int vector)
if (ipi_bitmap) {
ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
(unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr);
- WARN_ONCE(ret < 0, "KVM: failed to send PV IPI: %ld", ret);
+ WARN_ONCE(ret < 0, "kvm_guest: failed to send PV IPI: %ld",
+ ret);
}
local_irq_restore(flags);
@@ -509,7 +511,7 @@ static void kvm_setup_pv_ipi(void)
{
apic->send_IPI_mask = kvm_send_ipi_mask;
apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself;
- pr_info("KVM setup pv IPIs\n");
+ pr_info("setup PV IPIs\n");
}
static void kvm_smp_send_call_func_ipi(const struct cpumask *mask)
@@ -631,11 +633,11 @@ static void __init kvm_guest_init(void)
!kvm_para_has_hint(KVM_HINTS_REALTIME) &&
kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
smp_ops.send_call_func_ipi = kvm_smp_send_call_func_ipi;
- pr_info("KVM setup pv sched yield\n");
+ pr_info("setup PV sched yield\n");
}
if (cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/kvm:online",
kvm_cpu_online, kvm_cpu_down_prepare) < 0)
- pr_err("kvm_guest: Failed to install cpu hotplug callbacks\n");
+ pr_err("failed to install cpu hotplug callbacks\n");
#else
sev_map_percpu_data();
kvm_guest_cpu_init();
@@ -738,7 +740,7 @@ static __init int kvm_setup_pv_tlb_flush(void)
zalloc_cpumask_var_node(per_cpu_ptr(&__pv_tlb_mask, cpu),
GFP_KERNEL, cpu_to_node(cpu));
}
- pr_info("KVM setup pv remote TLB flush\n");
+ pr_info("setup PV remote TLB flush\n");
}
return 0;
@@ -866,8 +868,8 @@ static void kvm_enable_host_haltpoll(void *i)
void arch_haltpoll_enable(unsigned int cpu)
{
if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL)) {
- pr_err_once("kvm: host does not support poll control\n");
- pr_err_once("kvm: host upgrade recommended\n");
+ pr_err_once("host does not support poll control\n");
+ pr_err_once("host upgrade recommended\n");
return;
}
--
1.8.3.1
^ permalink raw reply related
* [PATCH v6 4/5] xen: Mark "xen_nopvspin" parameter obsolete
From: Zhenzhong Duan @ 2019-10-15 1:19 UTC (permalink / raw)
To: linux-kernel
Cc: vkuznets, linux-hyperv, kvm, kys, haiyangz, sthemmin, sashal,
tglx, mingo, bp, pbonzini, rkrcmar, sean.j.christopherson,
wanpengli, jmattson, joro, boris.ostrovsky, jgross, sstabellini,
peterz, Zhenzhong Duan, Jonathan Corbet, H. Peter Anvin
In-Reply-To: <1571102367-31595-1-git-send-email-zhenzhong.duan@oracle.com>
Map "xen_nopvspin" to "nopvspin", fix stale description of "xen_nopvspin"
as we use qspinlock now.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
Documentation/admin-guide/kernel-parameters.txt | 7 ++++---
arch/x86/xen/spinlock.c | 4 ++--
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index bd49ed2..85059dd 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5307,8 +5307,9 @@
panic() code such as dumping handler.
xen_nopvspin [X86,XEN]
- Disables the ticketlock slowpath using Xen PV
- optimizations.
+ Disables the qspinlock slowpath using Xen PV optimizations.
+ This parameter is obsoleted by "nopvspin" parameter, which
+ has equivalent effect for XEN platform.
xen_nopv [X86]
Disables the PV optimizations forcing the HVM guest to
@@ -5334,7 +5335,7 @@
as generic guest with no PV drivers. Currently support
XEN HVM, KVM, HYPER_V and VMWARE guest.
- nopvspin [X86,KVM]
+ nopvspin [X86,XEN,KVM]
Disables the qspinlock slow path using PV optimizations
which allow the hypervisor to 'idle' the guest on lock
contention.
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 6deb490..799f4eb 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -114,9 +114,8 @@ void xen_uninit_lock_cpu(int cpu)
*/
void __init xen_init_spinlocks(void)
{
-
/* Don't need to use pvqspinlock code if there is only 1 vCPU. */
- if (num_possible_cpus() == 1)
+ if (num_possible_cpus() == 1 || nopvspin)
xen_pvspin = false;
if (!xen_pvspin) {
@@ -137,6 +136,7 @@ void __init xen_init_spinlocks(void)
static __init int xen_parse_nopvspin(char *arg)
{
+ pr_notice("\"xen_nopvspin\" is deprecated, please use \"nopvspin\" instead\n");
xen_pvspin = false;
return 0;
}
--
1.8.3.1
^ permalink raw reply related
* [PATCH v6 3/5] x86/kvm: Add "nopvspin" parameter to disable PV spinlocks
From: Zhenzhong Duan @ 2019-10-15 1:19 UTC (permalink / raw)
To: linux-kernel
Cc: vkuznets, linux-hyperv, kvm, kys, haiyangz, sthemmin, sashal,
tglx, mingo, bp, pbonzini, rkrcmar, sean.j.christopherson,
wanpengli, jmattson, joro, boris.ostrovsky, jgross, sstabellini,
peterz, Zhenzhong Duan, Jonathan Corbet, H. Peter Anvin,
Will Deacon
In-Reply-To: <1571102367-31595-1-git-send-email-zhenzhong.duan@oracle.com>
There are cases where a guest tries to switch spinlocks to bare metal
behavior (e.g. by setting "xen_nopvspin" on XEN platform and
"hv_nopvspin" on HYPER_V).
That feature is missed on KVM, add a new parameter "nopvspin" to disable
PV spinlocks for KVM guest.
The new 'nopvspin' parameter will also replace Xen and Hyper-V specific
parameters in future patches.
Define variable nopvsin as global because it will be used in future
patches as above.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
---
Documentation/admin-guide/kernel-parameters.txt | 5 ++++
arch/x86/include/asm/qspinlock.h | 1 +
arch/x86/kernel/kvm.c | 34 ++++++++++++++++++++++---
kernel/locking/qspinlock.c | 7 +++++
4 files changed, 43 insertions(+), 4 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a84a83f..bd49ed2 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5334,6 +5334,11 @@
as generic guest with no PV drivers. Currently support
XEN HVM, KVM, HYPER_V and VMWARE guest.
+ nopvspin [X86,KVM]
+ Disables the qspinlock slow path using PV optimizations
+ which allow the hypervisor to 'idle' the guest on lock
+ contention.
+
xirc2ps_cs= [NET,PCMCIA]
Format:
<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h
index 444d6fd..d86ab94 100644
--- a/arch/x86/include/asm/qspinlock.h
+++ b/arch/x86/include/asm/qspinlock.h
@@ -32,6 +32,7 @@ static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lo
extern void __pv_init_lock_hash(void);
extern void __pv_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
extern void __raw_callee_save___pv_queued_spin_unlock(struct qspinlock *lock);
+extern bool nopvspin;
#define queued_spin_unlock queued_spin_unlock
/**
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 249f14a..e9c76d8 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -825,18 +825,44 @@ __visible bool __kvm_vcpu_is_preempted(long cpu)
*/
void __init kvm_spinlock_init(void)
{
- /* Does host kernel support KVM_FEATURE_PV_UNHALT? */
- if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT))
+ /*
+ * PV spinlocks is disabled if no host side support, then native
+ * qspinlock will be used. As native qspinlock is a fair lock, there is
+ * lock holder preemption issue using it in a guest, imaging one pCPU
+ * running 10 vCPUs of same guest contending same lock.
+ *
+ * virt_spin_lock() is introduced as an optimization for that scenario
+ * which is enabled by virt_spin_lock_key key. To use that optimization,
+ * virt_spin_lock_key isn't disabled here.
+ */
+ if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) {
+ pr_info("PV spinlocks disabled, no host support.\n");
return;
+ }
+ /*
+ * Disable PV qspinlock and use native qspinlock when dedicated pCPUs
+ * are available.
+ */
if (kvm_para_has_hint(KVM_HINTS_REALTIME)) {
+ pr_info("PV spinlocks disabled with KVM_HINTS_REALTIME hints.\n");
+ static_branch_disable(&virt_spin_lock_key);
+ return;
+ }
+
+ if (num_possible_cpus() == 1) {
+ pr_info("PV spinlocks disabled, single CPU.\n");
static_branch_disable(&virt_spin_lock_key);
return;
}
- /* Don't use the pvqspinlock code if there is only 1 vCPU. */
- if (num_possible_cpus() == 1)
+ if (nopvspin) {
+ pr_info("PV spinlocks disabled, forced by \"nopvspin\" parameter.\n");
+ static_branch_disable(&virt_spin_lock_key);
return;
+ }
+
+ pr_info("PV spinlocks enabled\n");
__pv_init_lock_hash();
pv_ops.lock.queued_spin_lock_slowpath = __pv_queued_spin_lock_slowpath;
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index 2473f10..75193d6 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -580,4 +580,11 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
#include "qspinlock_paravirt.h"
#include "qspinlock.c"
+bool nopvspin __initdata;
+static __init int parse_nopvspin(char *arg)
+{
+ nopvspin = true;
+ return 0;
+}
+early_param("nopvspin", parse_nopvspin);
#endif
--
1.8.3.1
^ permalink raw reply related
* [PATCH v6 5/5] x86/hyperv: Mark "hv_nopvspin" parameter obsolete
From: Zhenzhong Duan @ 2019-10-15 1:19 UTC (permalink / raw)
To: linux-kernel
Cc: vkuznets, linux-hyperv, kvm, kys, haiyangz, sthemmin, sashal,
tglx, mingo, bp, pbonzini, rkrcmar, sean.j.christopherson,
wanpengli, jmattson, joro, boris.ostrovsky, jgross, sstabellini,
peterz, Zhenzhong Duan, Jonathan Corbet, H. Peter Anvin
In-Reply-To: <1571102367-31595-1-git-send-email-zhenzhong.duan@oracle.com>
Map "hv_nopvspin" to "nopvspin".
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
Documentation/admin-guide/kernel-parameters.txt | 6 +++++-
arch/x86/hyperv/hv_spinlock.c | 4 ++++
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 85059dd..78648bb 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1436,6 +1436,10 @@
hv_nopvspin [X86,HYPER_V] Disables the paravirt spinlock optimizations
which allow the hypervisor to 'idle' the
guest on lock contention.
+ This parameter is obsoleted by "nopvspin"
+ parameter, which has equivalent effect for
+ HYPER_V platform.
+
keep_bootcon [KNL]
Do not unregister boot console at start. This is only
@@ -5335,7 +5339,7 @@
as generic guest with no PV drivers. Currently support
XEN HVM, KVM, HYPER_V and VMWARE guest.
- nopvspin [X86,XEN,KVM]
+ nopvspin [X86,XEN,KVM,HYPER_V]
Disables the qspinlock slow path using PV optimizations
which allow the hypervisor to 'idle' the guest on lock
contention.
diff --git a/arch/x86/hyperv/hv_spinlock.c b/arch/x86/hyperv/hv_spinlock.c
index 07f21a0..47c7d6c 100644
--- a/arch/x86/hyperv/hv_spinlock.c
+++ b/arch/x86/hyperv/hv_spinlock.c
@@ -64,6 +64,9 @@ __visible bool hv_vcpu_is_preempted(int vcpu)
void __init hv_init_spinlocks(void)
{
+ if (nopvspin)
+ hv_pvspin = false;
+
if (!hv_pvspin || !apic ||
!(ms_hyperv.hints & HV_X64_CLUSTER_IPI_RECOMMENDED) ||
!(ms_hyperv.features & HV_X64_MSR_GUEST_IDLE_AVAILABLE)) {
@@ -82,6 +85,7 @@ void __init hv_init_spinlocks(void)
static __init int hv_parse_nopvspin(char *arg)
{
+ pr_notice("\"hv_nopvspin\" is deprecated, please use \"nopvspin\" instead\n");
hv_pvspin = false;
return 0;
}
--
1.8.3.1
^ permalink raw reply related
* [PATCH v6 1/5] Revert "KVM: X86: Fix setup the virt_spin_lock_key before static key get initialized"
From: Zhenzhong Duan @ 2019-10-15 1:19 UTC (permalink / raw)
To: linux-kernel
Cc: vkuznets, linux-hyperv, kvm, kys, haiyangz, sthemmin, sashal,
tglx, mingo, bp, pbonzini, rkrcmar, sean.j.christopherson,
wanpengli, jmattson, joro, boris.ostrovsky, jgross, sstabellini,
peterz, Zhenzhong Duan, H. Peter Anvin
In-Reply-To: <1571102367-31595-1-git-send-email-zhenzhong.duan@oracle.com>
This reverts commit 34226b6b70980a8f81fff3c09a2c889f77edeeff.
Commit 8990cac6e5ea ("x86/jump_label: Initialize static branching
early") adds jump_label_init() call in setup_arch() to make static
keys initialized early, so we could use the original simpler code
again.
The similar change for XEN is in commit 090d54bcbc54 ("Revert
"x86/paravirt: Set up the virt_spin_lock_key after static keys get
initialized"")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
arch/x86/kernel/kvm.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index e820568..3bc6a266 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -527,13 +527,6 @@ static void kvm_smp_send_call_func_ipi(const struct cpumask *mask)
}
}
-static void __init kvm_smp_prepare_cpus(unsigned int max_cpus)
-{
- native_smp_prepare_cpus(max_cpus);
- if (kvm_para_has_hint(KVM_HINTS_REALTIME))
- static_branch_disable(&virt_spin_lock_key);
-}
-
static void __init kvm_smp_prepare_boot_cpu(void)
{
/*
@@ -633,7 +626,6 @@ static void __init kvm_guest_init(void)
apic_set_eoi_write(kvm_guest_apic_eoi_write);
#ifdef CONFIG_SMP
- smp_ops.smp_prepare_cpus = kvm_smp_prepare_cpus;
smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
if (kvm_para_has_feature(KVM_FEATURE_PV_SCHED_YIELD) &&
!kvm_para_has_hint(KVM_HINTS_REALTIME) &&
@@ -835,8 +827,10 @@ void __init kvm_spinlock_init(void)
if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT))
return;
- if (kvm_para_has_hint(KVM_HINTS_REALTIME))
+ if (kvm_para_has_hint(KVM_HINTS_REALTIME)) {
+ static_branch_disable(&virt_spin_lock_key);
return;
+ }
/* Don't use the pvqspinlock code if there is only 1 vCPU. */
if (num_possible_cpus() == 1)
--
1.8.3.1
^ permalink raw reply related
* [PATCH] x86/hyperv: Set pv_info.name to "Hyper-V"
From: Andrea Parri @ 2019-10-15 9:29 UTC (permalink / raw)
To: linux-kernel, linux-hyperv, x86
Cc: K . Y . Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, H . Peter Anvin,
Michael Kelley, Vitaly Kuznetsov, Dexuan Cui, Andrea Parri
Michael reported that the x86/hyperv initialization code printed the
following dmesg when running in a VM on Hyper-V:
[ 0.000738] Booting paravirtualized kernel on bare hardware
Let the x86/hyperv initialization code set pv_info.name to "Hyper-V";
with this addition, the dmesg read:
[ 0.000138] Booting paravirtualized kernel on Hyper-V
Reported-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
---
arch/x86/kernel/cpu/mshyperv.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 105844d542e5..c7d1801fa88b 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -154,6 +154,8 @@ static uint32_t __init ms_hyperv_platform(void)
if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
return 0;
+ pv_info.name = "Hyper-V";
+
cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
&eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
--
2.17.1
^ permalink raw reply related
* Re: [PATCH] x86/hyperv: Set pv_info.name to "Hyper-V"
From: Wei Liu @ 2019-10-15 9:39 UTC (permalink / raw)
To: Andrea Parri
Cc: Linux Kernel List, Linux on Hyper-V List, x86, K . Y . Srinivasan,
Haiyang Zhang, Stephen Hemminger, Sasha Levin, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, H . Peter Anvin, Michael Kelley,
Vitaly Kuznetsov, Dexuan Cui
In-Reply-To: <20191015092937.11244-1-parri.andrea@gmail.com>
On Tue, 15 Oct 2019 at 10:30, Andrea Parri <parri.andrea@gmail.com> wrote:
>
> Michael reported that the x86/hyperv initialization code printed the
> following dmesg when running in a VM on Hyper-V:
>
> [ 0.000738] Booting paravirtualized kernel on bare hardware
>
> Let the x86/hyperv initialization code set pv_info.name to "Hyper-V";
> with this addition, the dmesg read:
>
> [ 0.000138] Booting paravirtualized kernel on Hyper-V
>
> Reported-by: Michael Kelley <mikelley@microsoft.com>
> Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
> ---
> arch/x86/kernel/cpu/mshyperv.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> index 105844d542e5..c7d1801fa88b 100644
> --- a/arch/x86/kernel/cpu/mshyperv.c
> +++ b/arch/x86/kernel/cpu/mshyperv.c
> @@ -154,6 +154,8 @@ static uint32_t __init ms_hyperv_platform(void)
This function is for platform detection only.
> if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
> return 0;
>
> + pv_info.name = "Hyper-V";
> +
At this point we're not sure if Linux is really running on Hyper-V yet.
Setting pv_info.name should be moved to the init_platform hook, i.e.
ms_hyperv_init_platform.
Wei.
> cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
> &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
>
> --
> 2.17.1
>
^ permalink raw reply
* Re: [PATCH] x86/hyperv: Set pv_info.name to "Hyper-V"
From: Andrea Parri @ 2019-10-15 10:25 UTC (permalink / raw)
To: Wei Liu
Cc: Linux Kernel List, Linux on Hyper-V List, x86, K . Y . Srinivasan,
Haiyang Zhang, Stephen Hemminger, Sasha Levin, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, H . Peter Anvin, Michael Kelley,
Vitaly Kuznetsov, Dexuan Cui
In-Reply-To: <CAHd7Wqxn3sQQWkzOBrJ1KYm8eUpwa_9dcSYRDfPGAMWm=qvbag@mail.gmail.com>
> > @@ -154,6 +154,8 @@ static uint32_t __init ms_hyperv_platform(void)
>
> This function is for platform detection only.
>
> > if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
> > return 0;
> >
> > + pv_info.name = "Hyper-V";
> > +
>
> At this point we're not sure if Linux is really running on Hyper-V yet.
>
> Setting pv_info.name should be moved to the init_platform hook, i.e.
> ms_hyperv_init_platform.
Thank you for the review, Wei. I'll move this to the init_platform hook
and re-submit shortly.
Thanks,
Andrea
^ permalink raw reply
* [PATCH v2] x86/hyperv: Set pv_info.name to "Hyper-V"
From: Andrea Parri @ 2019-10-15 10:35 UTC (permalink / raw)
To: linux-kernel, linux-hyperv, x86
Cc: K . Y . Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, H . Peter Anvin,
Michael Kelley, Vitaly Kuznetsov, Dexuan Cui, Wei Liu,
Andrea Parri
Michael reported that the x86/hyperv initialization code printed the
following dmesg when running in a VM on Hyper-V:
[ 0.000738] Booting paravirtualized kernel on bare hardware
Let the x86/hyperv initialization code set pv_info.name to "Hyper-V";
with this addition, the dmesg read:
[ 0.000172] Booting paravirtualized kernel on Hyper-V
Reported-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
---
Changes since v1 ([1]):
- move the setting of pv_info.name to ms_hyperv_init_platform() (Wei Liu)
[1] https://lkml.kernel.org/r/20191015092937.11244-1-parri.andrea@gmail.com
arch/x86/kernel/cpu/mshyperv.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 267daad8c0360..e7f0776e2a811 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -216,6 +216,8 @@ static void __init ms_hyperv_init_platform(void)
int hv_host_info_ecx;
int hv_host_info_edx;
+ pv_info.name = "Hyper-V";
+
/*
* Extract the features and hints
*/
--
2.23.0
^ permalink raw reply related
* Re: [PATCH v2] x86/hyperv: Set pv_info.name to "Hyper-V"
From: Wei Liu @ 2019-10-15 10:56 UTC (permalink / raw)
To: Andrea Parri
Cc: Linux Kernel List, Linux on Hyper-V List, x86, K . Y . Srinivasan,
Haiyang Zhang, Stephen Hemminger, Sasha Levin, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, H . Peter Anvin, Michael Kelley,
Vitaly Kuznetsov, Dexuan Cui, Wei Liu
In-Reply-To: <20191015103502.13156-1-parri.andrea@gmail.com>
On Tue, 15 Oct 2019 at 11:35, Andrea Parri <parri.andrea@gmail.com> wrote:
>
> Michael reported that the x86/hyperv initialization code printed the
> following dmesg when running in a VM on Hyper-V:
>
> [ 0.000738] Booting paravirtualized kernel on bare hardware
>
> Let the x86/hyperv initialization code set pv_info.name to "Hyper-V";
> with this addition, the dmesg read:
>
> [ 0.000172] Booting paravirtualized kernel on Hyper-V
>
> Reported-by: Michael Kelley <mikelley@microsoft.com>
> Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
^ permalink raw reply
* [PATCH v3 0/3] Drivers: hv: vmbus: Miscellaneous improvements
From: Andrea Parri @ 2019-10-15 11:46 UTC (permalink / raw)
To: linux-kernel, linux-hyperv
Cc: K . Y . Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
Michael Kelley, Vitaly Kuznetsov, Dexuan Cui, Wei Liu,
Andrea Parri
Hi all,
The patchset:
- refactors the VMBus negotiation code by introducing the table of
VMBus protocol versions (patch 1/3),
- enables VMBus protocol version 4.1, 5.1 and 5.2 (patch 2/3),
- introduces a module parameter to cap the VMBus protocol versions
which a guest can negotiate with the hypervisor (patch 3/3).
Thanks,
Andrea
---
Changes since v2 ([1]):
- refactor the loop exit path in vmbus_connect() (Michael Kelley)
- do not rename VERSION_WIN10 (Michael Kelley)
Changes since v1 ([2]):
- remove the VERSION_INVAL macro (Vitaly Kuznetsov and Dexuan Cui)
- make the table of VMBus protocol versions static (Dexuan Cui)
- enable VMBus protocol version 4.1 (Michael Kelley)
- introduce module parameter to cap the VMBus version (Dexuan Cui)
[1] https://lkml.kernel.org/r/20191010154600.23875-1-parri.andrea@gmail.com
[2] https://lkml.kernel.org/r/20191007163115.26197-1-parri.andrea@gmail.com
Andrea Parri (3):
Drivers: hv: vmbus: Introduce table of VMBus protocol versions
Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2
Drivers: hv: vmbus: Add module parameter to cap the VMBus version
drivers/hv/connection.c | 72 +++++++++++++++++++++--------------------
drivers/hv/vmbus_drv.c | 3 +-
include/linux/hyperv.h | 12 ++++---
3 files changed, 45 insertions(+), 42 deletions(-)
--
2.23.0
^ permalink raw reply
* [PATCH v3 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions
From: Andrea Parri @ 2019-10-15 11:46 UTC (permalink / raw)
To: linux-kernel, linux-hyperv
Cc: K . Y . Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
Michael Kelley, Vitaly Kuznetsov, Dexuan Cui, Wei Liu,
Andrea Parri
In-Reply-To: <20191015114646.15354-1-parri.andrea@gmail.com>
The technique used to get the next VMBus version seems increasisly
clumsy as the number of VMBus versions increases. Performance is
not a concern since this is only done once during system boot; it's
just that we'll end up with more lines of code than is really needed.
As an alternative, introduce a table with the version numbers listed
in order (from the most recent to the oldest). vmbus_connect() loops
through the versions listed in the table until it gets an accepted
connection or gets to the end of the table (invalid version).
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
---
drivers/hv/connection.c | 50 +++++++++++++++--------------------------
drivers/hv/vmbus_drv.c | 3 +--
include/linux/hyperv.h | 4 ----
3 files changed, 19 insertions(+), 38 deletions(-)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 6e4c015783ffc..8dc48f53c1ac4 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -40,29 +40,17 @@ EXPORT_SYMBOL_GPL(vmbus_connection);
__u32 vmbus_proto_version;
EXPORT_SYMBOL_GPL(vmbus_proto_version);
-static __u32 vmbus_get_next_version(__u32 current_version)
-{
- switch (current_version) {
- case (VERSION_WIN7):
- return VERSION_WS2008;
-
- case (VERSION_WIN8):
- return VERSION_WIN7;
-
- case (VERSION_WIN8_1):
- return VERSION_WIN8;
-
- case (VERSION_WIN10):
- return VERSION_WIN8_1;
-
- case (VERSION_WIN10_V5):
- return VERSION_WIN10;
-
- case (VERSION_WS2008):
- default:
- return VERSION_INVAL;
- }
-}
+/*
+ * Table of VMBus versions listed from newest to oldest.
+ */
+static __u32 vmbus_versions[] = {
+ VERSION_WIN10_V5,
+ VERSION_WIN10,
+ VERSION_WIN8_1,
+ VERSION_WIN8,
+ VERSION_WIN7,
+ VERSION_WS2008
+};
int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
{
@@ -169,8 +157,8 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
*/
int vmbus_connect(void)
{
- int ret = 0;
struct vmbus_channel_msginfo *msginfo = NULL;
+ int i, ret = 0;
__u32 version;
/* Initialize the vmbus connection */
@@ -244,21 +232,19 @@ int vmbus_connect(void)
* version.
*/
- version = VERSION_CURRENT;
+ for (i = 0; ; i++) {
+ if (i == ARRAY_SIZE(vmbus_versions))
+ goto cleanup;
+
+ version = vmbus_versions[i];
- do {
ret = vmbus_negotiate_version(msginfo, version);
if (ret == -ETIMEDOUT)
goto cleanup;
if (vmbus_connection.conn_state == CONNECTED)
break;
-
- version = vmbus_get_next_version(version);
- } while (version != VERSION_INVAL);
-
- if (version == VERSION_INVAL)
- goto cleanup;
+ }
vmbus_proto_version = version;
pr_info("Vmbus version:%d.%d\n",
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 53a60c81e220d..0ac874faf7209 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -2220,8 +2220,7 @@ static int vmbus_bus_resume(struct device *dev)
* We only use the 'vmbus_proto_version', which was in use before
* hibernation, to re-negotiate with the host.
*/
- if (vmbus_proto_version == VERSION_INVAL ||
- vmbus_proto_version == 0) {
+ if (!vmbus_proto_version) {
pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
return -EINVAL;
}
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index b4a017093b697..c08b62dbd151f 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -192,10 +192,6 @@ static inline u32 hv_get_avail_to_write_percent(
#define VERSION_WIN10 ((4 << 16) | (0))
#define VERSION_WIN10_V5 ((5 << 16) | (0))
-#define VERSION_INVAL -1
-
-#define VERSION_CURRENT VERSION_WIN10_V5
-
/* Make maximum size of pipe payload of 16K */
#define MAX_PIPE_DATA_PAYLOAD (sizeof(u8) * 16384)
--
2.23.0
^ permalink raw reply related
* [PATCH v3 2/3] Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2
From: Andrea Parri @ 2019-10-15 11:46 UTC (permalink / raw)
To: linux-kernel, linux-hyperv
Cc: K . Y . Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
Michael Kelley, Vitaly Kuznetsov, Dexuan Cui, Wei Liu,
Andrea Parri
In-Reply-To: <20191015114646.15354-1-parri.andrea@gmail.com>
Hyper-V has added VMBus protocol versions 5.1 and 5.2 in recent release
versions. Allow Linux guests to negotiate these new protocol versions
on versions of Hyper-V that support them. While on this, also allow
guests to negotiate the VMBus protocol version 4.1 (which was missing).
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
---
drivers/hv/connection.c | 13 ++++++++-----
include/linux/hyperv.h | 8 +++++++-
2 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 8dc48f53c1ac4..cadfb34b38d80 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -44,7 +44,10 @@ EXPORT_SYMBOL_GPL(vmbus_proto_version);
* Table of VMBus versions listed from newest to oldest.
*/
static __u32 vmbus_versions[] = {
+ VERSION_WIN10_V5_2,
+ VERSION_WIN10_V5_1,
VERSION_WIN10_V5,
+ VERSION_WIN10_V4_1,
VERSION_WIN10,
VERSION_WIN8_1,
VERSION_WIN8,
@@ -68,12 +71,12 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
msg->vmbus_version_requested = version;
/*
- * VMBus protocol 5.0 (VERSION_WIN10_V5) requires that we must use
- * VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate Contact Message,
+ * VMBus protocol 5.0 (VERSION_WIN10_V5) and higher require that we must
+ * use VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate Contact Message,
* and for subsequent messages, we must use the Message Connection ID
* field in the host-returned Version Response Message. And, with
- * VERSION_WIN10_V5, we don't use msg->interrupt_page, but we tell
- * the host explicitly that we still use VMBUS_MESSAGE_SINT(2) for
+ * VERSION_WIN10_V5 and higher, we don't use msg->interrupt_page, but we
+ * tell the host explicitly that we still use VMBUS_MESSAGE_SINT(2) for
* compatibility.
*
* On old hosts, we should always use VMBUS_MESSAGE_CONNECTION_ID (1).
@@ -399,7 +402,7 @@ int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep)
case HV_STATUS_INVALID_CONNECTION_ID:
/*
* See vmbus_negotiate_version(): VMBus protocol 5.0
- * requires that we must use
+ * and higher require that we must use
* VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate
* Contact message, but on old hosts that only
* support VMBus protocol 4.0 or lower, here we get
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index c08b62dbd151f..f17f2cd22e39f 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -182,15 +182,21 @@ static inline u32 hv_get_avail_to_write_percent(
* 2 . 4 (Windows 8)
* 3 . 0 (Windows 8 R2)
* 4 . 0 (Windows 10)
+ * 4 . 1 (Windows 10 RS3)
* 5 . 0 (Newer Windows 10)
+ * 5 . 1 (Windows 10 RS4)
+ * 5 . 2 (Windows Server 2019, RS5)
*/
#define VERSION_WS2008 ((0 << 16) | (13))
#define VERSION_WIN7 ((1 << 16) | (1))
#define VERSION_WIN8 ((2 << 16) | (4))
#define VERSION_WIN8_1 ((3 << 16) | (0))
-#define VERSION_WIN10 ((4 << 16) | (0))
+#define VERSION_WIN10 ((4 << 16) | (0))
+#define VERSION_WIN10_V4_1 ((4 << 16) | (1))
#define VERSION_WIN10_V5 ((5 << 16) | (0))
+#define VERSION_WIN10_V5_1 ((5 << 16) | (1))
+#define VERSION_WIN10_V5_2 ((5 << 16) | (2))
/* Make maximum size of pipe payload of 16K */
#define MAX_PIPE_DATA_PAYLOAD (sizeof(u8) * 16384)
--
2.23.0
^ permalink raw reply related
* [PATCH v3 3/3] Drivers: hv: vmbus: Add module parameter to cap the VMBus version
From: Andrea Parri @ 2019-10-15 11:46 UTC (permalink / raw)
To: linux-kernel, linux-hyperv
Cc: K . Y . Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
Michael Kelley, Vitaly Kuznetsov, Dexuan Cui, Wei Liu,
Andrea Parri
In-Reply-To: <20191015114646.15354-1-parri.andrea@gmail.com>
Currently, Linux guests negotiate the VMBus version with Hyper-V
and use the highest available VMBus version they can connect to.
This has some drawbacks: by using the highest available version,
certain code paths are never executed and can not be tested when
the guest runs on the newest host.
Add the module parameter "max_version", to upper-bound the VMBus
versions guests can negotiate.
Suggested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
---
drivers/hv/connection.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index cadfb34b38d80..0475be4356dd7 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -14,6 +14,7 @@
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/mm.h>
+#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/hyperv.h>
@@ -55,6 +56,16 @@ static __u32 vmbus_versions[] = {
VERSION_WS2008
};
+/*
+ * Maximal VMBus protocol version guests can negotiate. Useful to cap the
+ * VMBus version for testing and debugging purpose.
+ */
+static uint max_version = VERSION_WIN10_V5_2;
+
+module_param(max_version, uint, S_IRUGO);
+MODULE_PARM_DESC(max_version,
+ "Maximal VMBus protocol version which can be negotiated");
+
int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
{
int ret = 0;
@@ -240,6 +251,8 @@ int vmbus_connect(void)
goto cleanup;
version = vmbus_versions[i];
+ if (version > max_version)
+ continue;
ret = vmbus_negotiate_version(msginfo, version);
if (ret == -ETIMEDOUT)
--
2.23.0
^ permalink raw reply related
* RE: [PATCH v2] x86/hyperv: Set pv_info.name to "Hyper-V"
From: Michael Kelley @ 2019-10-15 13:06 UTC (permalink / raw)
To: Andrea Parri, linux-kernel@vger.kernel.org,
linux-hyperv@vger.kernel.org, x86@kernel.org
Cc: KY Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, H . Peter Anvin,
vkuznets, Dexuan Cui, Wei Liu
In-Reply-To: <20191015103502.13156-1-parri.andrea@gmail.com>
From: Andrea Parri <parri.andrea@gmail.com> Sent: Tuesday, October 15, 2019 3:35 AM
>
> Michael reported that the x86/hyperv initialization code printed the
> following dmesg when running in a VM on Hyper-V:
>
> [ 0.000738] Booting paravirtualized kernel on bare hardware
>
> Let the x86/hyperv initialization code set pv_info.name to "Hyper-V";
> with this addition, the dmesg read:
>
> [ 0.000172] Booting paravirtualized kernel on Hyper-V
>
> Reported-by: Michael Kelley <mikelley@microsoft.com>
> Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
^ permalink raw reply
* RE: [PATCH v3 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions
From: Michael Kelley @ 2019-10-15 13:08 UTC (permalink / raw)
To: Andrea Parri, linux-kernel@vger.kernel.org,
linux-hyperv@vger.kernel.org
Cc: KY Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
vkuznets, Dexuan Cui, Wei Liu
In-Reply-To: <20191015114646.15354-2-parri.andrea@gmail.com>
From: Andrea Parri <parri.andrea@gmail.com> Sent: Tuesday, October 15, 2019 4:47 AM
>
> The technique used to get the next VMBus version seems increasisly
> clumsy as the number of VMBus versions increases. Performance is
> not a concern since this is only done once during system boot; it's
> just that we'll end up with more lines of code than is really needed.
>
> As an alternative, introduce a table with the version numbers listed
> in order (from the most recent to the oldest). vmbus_connect() loops
> through the versions listed in the table until it gets an accepted
> connection or gets to the end of the table (invalid version).
>
> Suggested-by: Michael Kelley <mikelley@microsoft.com>
> Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
> ---
> drivers/hv/connection.c | 50 +++++++++++++++--------------------------
> drivers/hv/vmbus_drv.c | 3 +--
> include/linux/hyperv.h | 4 ----
> 3 files changed, 19 insertions(+), 38 deletions(-)
>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
^ permalink raw reply
* RE: [PATCH v3 2/3] Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2
From: Michael Kelley @ 2019-10-15 13:12 UTC (permalink / raw)
To: Andrea Parri, linux-kernel@vger.kernel.org,
linux-hyperv@vger.kernel.org
Cc: KY Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
vkuznets, Dexuan Cui, Wei Liu
In-Reply-To: <20191015114646.15354-3-parri.andrea@gmail.com>
From: Andrea Parri <parri.andrea@gmail.com> Sent: Tuesday, October 15, 2019 4:47 AM
>
> Hyper-V has added VMBus protocol versions 5.1 and 5.2 in recent release
> versions. Allow Linux guests to negotiate these new protocol versions
> on versions of Hyper-V that support them. While on this, also allow
> guests to negotiate the VMBus protocol version 4.1 (which was missing).
>
> Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
> ---
> drivers/hv/connection.c | 13 ++++++++-----
> include/linux/hyperv.h | 8 +++++++-
> 2 files changed, 15 insertions(+), 6 deletions(-)
>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
^ permalink raw reply
* RE: [PATCH v3 3/3] Drivers: hv: vmbus: Add module parameter to cap the VMBus version
From: Michael Kelley @ 2019-10-15 13:15 UTC (permalink / raw)
To: Andrea Parri, linux-kernel@vger.kernel.org,
linux-hyperv@vger.kernel.org
Cc: KY Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
vkuznets, Dexuan Cui, Wei Liu
In-Reply-To: <20191015114646.15354-4-parri.andrea@gmail.com>
From: Andrea Parri <parri.andrea@gmail.com> Sent: Tuesday, October 15, 2019 4:47 AM
>
> Currently, Linux guests negotiate the VMBus version with Hyper-V
> and use the highest available VMBus version they can connect to.
> This has some drawbacks: by using the highest available version,
> certain code paths are never executed and can not be tested when
> the guest runs on the newest host.
>
> Add the module parameter "max_version", to upper-bound the VMBus
> versions guests can negotiate.
>
> Suggested-by: Dexuan Cui <decui@microsoft.com>
> Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
> ---
> drivers/hv/connection.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
^ permalink raw reply
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