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authorLinus Torvalds <torvalds@linux-foundation.org>2022-04-07 06:35:34 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-07 06:35:34 -1000
commit42e7a03d3badebd4e70aea5362d6914dfc7c220b (patch)
tree4024ddc668d571c521becb0a48452a09c020f5bb /drivers/hv
parent3638bd90df9930511fa85f9a811d02feee4e0b97 (diff)
parenteaa03d34535872d29004cb5cf77dc9dec1ba9a25 (diff)
Merge tag 'hyperv-fixes-signed-20220407' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv fixes from Wei Liu: - Correctly propagate coherence information for VMbus devices (Michael Kelley) - Disable balloon and memory hot-add on ARM64 temporarily (Boqun Feng) - Use barrier to prevent reording when reading ring buffer (Michael Kelley) - Use virt_store_mb in favour of smp_store_mb (Andrea Parri) - Fix VMbus device object initialization (Andrea Parri) - Deactivate sysctl_record_panic_msg on isolated guest (Andrea Parri) - Fix a crash when unloading VMbus module (Guilherme G. Piccoli) * tag 'hyperv-fixes-signed-20220407' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Drivers: hv: vmbus: Replace smp_store_mb() with virt_store_mb() Drivers: hv: balloon: Disable balloon and hot-add accordingly Drivers: hv: balloon: Support status report for larger page sizes Drivers: hv: vmbus: Prevent load re-ordering when reading ring buffer PCI: hv: Propagate coherence from VMbus device to PCI device Drivers: hv: vmbus: Propagate VMbus coherence to each VMbus device Drivers: hv: vmbus: Fix potential crash on module unload Drivers: hv: vmbus: Fix initialization of device object in vmbus_device_register() Drivers: hv: vmbus: Deactivate sysctl_record_panic_msg by default in isolated guests
Diffstat (limited to 'drivers/hv')
-rw-r--r--drivers/hv/channel_mgmt.c6
-rw-r--r--drivers/hv/hv_balloon.c49
-rw-r--r--drivers/hv/hv_common.c11
-rw-r--r--drivers/hv/ring_buffer.c11
-rw-r--r--drivers/hv/vmbus_drv.c65
5 files changed, 122 insertions, 20 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 26d269ba947c..85a2142c9384 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -380,7 +380,7 @@ void vmbus_channel_map_relid(struct vmbus_channel *channel)
* execute:
*
* (a) In the "normal (i.e., not resuming from hibernation)" path,
- * the full barrier in smp_store_mb() guarantees that the store
+ * the full barrier in virt_store_mb() guarantees that the store
* is propagated to all CPUs before the add_channel_work work
* is queued. In turn, add_channel_work is queued before the
* channel's ring buffer is allocated/initialized and the
@@ -392,14 +392,14 @@ void vmbus_channel_map_relid(struct vmbus_channel *channel)
* recv_int_page before retrieving the channel pointer from the
* array of channels.
*
- * (b) In the "resuming from hibernation" path, the smp_store_mb()
+ * (b) In the "resuming from hibernation" path, the virt_store_mb()
* guarantees that the store is propagated to all CPUs before
* the VMBus connection is marked as ready for the resume event
* (cf. check_ready_for_resume_event()). The interrupt handler
* of the VMBus driver and vmbus_chan_sched() can not run before
* vmbus_bus_resume() has completed execution (cf. resume_noirq).
*/
- smp_store_mb(
+ virt_store_mb(
vmbus_connection.channels[channel->offermsg.child_relid],
channel);
}
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 439f99b8b5de..3248b48f37f6 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -17,6 +17,7 @@
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/completion.h>
+#include <linux/count_zeros.h>
#include <linux/memory_hotplug.h>
#include <linux/memory.h>
#include <linux/notifier.h>
@@ -1130,6 +1131,7 @@ static void post_status(struct hv_dynmem_device *dm)
struct dm_status status;
unsigned long now = jiffies;
unsigned long last_post = last_post_time;
+ unsigned long num_pages_avail, num_pages_committed;
if (pressure_report_delay > 0) {
--pressure_report_delay;
@@ -1154,16 +1156,21 @@ static void post_status(struct hv_dynmem_device *dm)
* num_pages_onlined) as committed to the host, otherwise it can try
* asking us to balloon them out.
*/
- status.num_avail = si_mem_available();
- status.num_committed = vm_memory_committed() +
+ num_pages_avail = si_mem_available();
+ num_pages_committed = vm_memory_committed() +
dm->num_pages_ballooned +
(dm->num_pages_added > dm->num_pages_onlined ?
dm->num_pages_added - dm->num_pages_onlined : 0) +
compute_balloon_floor();
- trace_balloon_status(status.num_avail, status.num_committed,
+ trace_balloon_status(num_pages_avail, num_pages_committed,
vm_memory_committed(), dm->num_pages_ballooned,
dm->num_pages_added, dm->num_pages_onlined);
+
+ /* Convert numbers of pages into numbers of HV_HYP_PAGEs. */
+ status.num_avail = num_pages_avail * NR_HV_HYP_PAGES_IN_PAGE;
+ status.num_committed = num_pages_committed * NR_HV_HYP_PAGES_IN_PAGE;
+
/*
* If our transaction ID is no longer current, just don't
* send the status. This can happen if we were interrupted
@@ -1653,6 +1660,38 @@ static void disable_page_reporting(void)
}
}
+static int ballooning_enabled(void)
+{
+ /*
+ * Disable ballooning if the page size is not 4k (HV_HYP_PAGE_SIZE),
+ * since currently it's unclear to us whether an unballoon request can
+ * make sure all page ranges are guest page size aligned.
+ */
+ if (PAGE_SIZE != HV_HYP_PAGE_SIZE) {
+ pr_info("Ballooning disabled because page size is not 4096 bytes\n");
+ return 0;
+ }
+
+ return 1;
+}
+
+static int hot_add_enabled(void)
+{
+ /*
+ * Disable hot add on ARM64, because we currently rely on
+ * memory_add_physaddr_to_nid() to get a node id of a hot add range,
+ * however ARM64's memory_add_physaddr_to_nid() always return 0 and
+ * DM_MEM_HOT_ADD_REQUEST doesn't have the NUMA node information for
+ * add_memory().
+ */
+ if (IS_ENABLED(CONFIG_ARM64)) {
+ pr_info("Memory hot add disabled on ARM64\n");
+ return 0;
+ }
+
+ return 1;
+}
+
static int balloon_connect_vsp(struct hv_device *dev)
{
struct dm_version_request version_req;
@@ -1724,8 +1763,8 @@ static int balloon_connect_vsp(struct hv_device *dev)
* currently still requires the bits to be set, so we have to add code
* to fail the host's hot-add and balloon up/down requests, if any.
*/
- cap_msg.caps.cap_bits.balloon = 1;
- cap_msg.caps.cap_bits.hot_add = 1;
+ cap_msg.caps.cap_bits.balloon = ballooning_enabled();
+ cap_msg.caps.cap_bits.hot_add = hot_add_enabled();
/*
* Specify our alignment requirements as it relates
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index c1dd21d0d7ef..ae68298c0dca 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -20,6 +20,7 @@
#include <linux/panic_notifier.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
+#include <linux/dma-map-ops.h>
#include <asm/hyperv-tlfs.h>
#include <asm/mshyperv.h>
@@ -218,6 +219,16 @@ bool hv_query_ext_cap(u64 cap_query)
}
EXPORT_SYMBOL_GPL(hv_query_ext_cap);
+void hv_setup_dma_ops(struct device *dev, bool coherent)
+{
+ /*
+ * Hyper-V does not offer a vIOMMU in the guest
+ * VM, so pass 0/NULL for the IOMMU settings
+ */
+ arch_setup_dma_ops(dev, 0, 0, NULL, coherent);
+}
+EXPORT_SYMBOL_GPL(hv_setup_dma_ops);
+
bool hv_is_hibernation_supported(void)
{
return !hv_root_partition && acpi_sleep_state_supported(ACPI_STATE_S4);
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 71efacb90965..3d215d9dec43 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -439,7 +439,16 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
static u32 hv_pkt_iter_avail(const struct hv_ring_buffer_info *rbi)
{
u32 priv_read_loc = rbi->priv_read_index;
- u32 write_loc = READ_ONCE(rbi->ring_buffer->write_index);
+ u32 write_loc;
+
+ /*
+ * The Hyper-V host writes the packet data, then uses
+ * store_release() to update the write_index. Use load_acquire()
+ * here to prevent loads of the packet data from being re-ordered
+ * before the read of the write_index and potentially getting
+ * stale data.
+ */
+ write_loc = virt_load_acquire(&rbi->ring_buffer->write_index);
if (write_loc >= priv_read_loc)
return write_loc - priv_read_loc;
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 60ee8b329f9e..14de17087864 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -77,8 +77,8 @@ static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
/*
* Hyper-V should be notified only once about a panic. If we will be
- * doing hyperv_report_panic_msg() later with kmsg data, don't do
- * the notification here.
+ * doing hv_kmsg_dump() with kmsg data later, don't do the notification
+ * here.
*/
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
&& hyperv_report_reg()) {
@@ -100,8 +100,8 @@ static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
/*
* Hyper-V should be notified only once about a panic. If we will be
- * doing hyperv_report_panic_msg() later with kmsg data, don't do
- * the notification here.
+ * doing hv_kmsg_dump() with kmsg data later, don't do the notification
+ * here.
*/
if (hyperv_report_reg())
hyperv_report_panic(regs, val, true);
@@ -921,6 +921,21 @@ static int vmbus_probe(struct device *child_device)
}
/*
+ * vmbus_dma_configure -- Configure DMA coherence for VMbus device
+ */
+static int vmbus_dma_configure(struct device *child_device)
+{
+ /*
+ * On ARM64, propagate the DMA coherence setting from the top level
+ * VMbus ACPI device to the child VMbus device being added here.
+ * On x86/x64 coherence is assumed and these calls have no effect.
+ */
+ hv_setup_dma_ops(child_device,
+ device_get_dma_attr(&hv_acpi_dev->dev) == DEV_DMA_COHERENT);
+ return 0;
+}
+
+/*
* vmbus_remove - Remove a vmbus device
*/
static void vmbus_remove(struct device *child_device)
@@ -1040,6 +1055,7 @@ static struct bus_type hv_bus = {
.remove = vmbus_remove,
.probe = vmbus_probe,
.uevent = vmbus_uevent,
+ .dma_configure = vmbus_dma_configure,
.dev_groups = vmbus_dev_groups,
.drv_groups = vmbus_drv_groups,
.bus_groups = vmbus_bus_groups,
@@ -1546,14 +1562,20 @@ static int vmbus_bus_init(void)
if (ret)
goto err_connect;
+ if (hv_is_isolation_supported())
+ sysctl_record_panic_msg = 0;
+
/*
* Only register if the crash MSRs are available
*/
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
u64 hyperv_crash_ctl;
/*
- * Sysctl registration is not fatal, since by default
- * reporting is enabled.
+ * Panic message recording (sysctl_record_panic_msg)
+ * is enabled by default in non-isolated guests and
+ * disabled by default in isolated guests; the panic
+ * message recording won't be available in isolated
+ * guests should the following registration fail.
*/
hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
if (!hv_ctl_table_hdr)
@@ -2097,6 +2119,10 @@ int vmbus_device_register(struct hv_device *child_device_obj)
child_device_obj->device.parent = &hv_acpi_dev->dev;
child_device_obj->device.release = vmbus_device_release;
+ child_device_obj->device.dma_parms = &child_device_obj->dma_parms;
+ child_device_obj->device.dma_mask = &child_device_obj->dma_mask;
+ dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64));
+
/*
* Register with the LDM. This will kick off the driver/device
* binding...which will eventually call vmbus_match() and vmbus_probe()
@@ -2122,9 +2148,6 @@ int vmbus_device_register(struct hv_device *child_device_obj)
}
hv_debug_add_dev_dir(child_device_obj);
- child_device_obj->device.dma_parms = &child_device_obj->dma_parms;
- child_device_obj->device.dma_mask = &child_device_obj->dma_mask;
- dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64));
return 0;
err_kset_unregister:
@@ -2428,6 +2451,21 @@ static int vmbus_acpi_add(struct acpi_device *device)
hv_acpi_dev = device;
+ /*
+ * Older versions of Hyper-V for ARM64 fail to include the _CCA
+ * method on the top level VMbus device in the DSDT. But devices
+ * are hardware coherent in all current Hyper-V use cases, so fix
+ * up the ACPI device to behave as if _CCA is present and indicates
+ * hardware coherence.
+ */
+ ACPI_COMPANION_SET(&device->dev, device);
+ if (IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED) &&
+ device_get_dma_attr(&device->dev) == DEV_DMA_NOT_SUPPORTED) {
+ pr_info("No ACPI _CCA found; assuming coherent device I/O\n");
+ device->flags.cca_seen = true;
+ device->flags.coherent_dma = true;
+ }
+
result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
vmbus_walk_resources, NULL);
@@ -2780,10 +2818,15 @@ static void __exit vmbus_exit(void)
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
kmsg_dump_unregister(&hv_kmsg_dumper);
unregister_die_notifier(&hyperv_die_block);
- atomic_notifier_chain_unregister(&panic_notifier_list,
- &hyperv_panic_block);
}
+ /*
+ * The panic notifier is always registered, hence we should
+ * also unconditionally unregister it here as well.
+ */
+ atomic_notifier_chain_unregister(&panic_notifier_list,
+ &hyperv_panic_block);
+
free_page((unsigned long)hv_panic_page);
unregister_sysctl_table(hv_ctl_table_hdr);
hv_ctl_table_hdr = NULL;