virtio_blk: set the zone write granularitygrafted

virtblk_read_zoned_limits() reads the write granularity that the device
reports in virtio_blk_zoned_characteristics and assigns it to the
physical block size and to io_min, but never to the limit that is named
after it. queue_limits.zone_write_granularity is left at zero, so
blk_validate_zoned_limits() raises it to the logical block size:

	if (lim->zone_write_granularity < lim->logical_block_size)
		lim->zone_write_granularity = lim->logical_block_size;

A device that reports a granularity coarser than its logical block size,
which is what the field exists to express, therefore has it silently
reduced. A 512e host managed disk passed through to a guest reports a
logical block size of 512 and a write granularity of 4096, and the guest
ends up with a zone write granularity of 512.

bio_split_alignment() returns lim->zone_write_granularity if it is non-zero
and bio_split_io_at() may split a bio with as per bio_split_alignment().
This can real to the write getting rejected by the host drive, as the write
is not aligned to the physical block size.

zonefs also takes its block size from bdev_zone_write_granularity(), so it
would incorrectly use 512 on a disk that requires 4096.

sd_zbc_read_zones() sets the limit from the physical block size for the
same reason. NVMe ZNS and null_blk leave it unset, but the fallback
gives the right answer for them, as their write granularity is the
logical block size. virtio carries a separate value that may exceed it.

Set the zone write granularity from the value that the device reports.

Fixes: 95bfec41bd3d ("virtio-blk: add support for zoned block devices")
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://patch.msgid.link/20260918140641.2031075-2-cassel@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 173 insertions, 0 deletions

diff --git a/drivers/clocksource/timer-mp-csky.c b/drivers/clocksource/timer-mp-csky.c
new file mode 100644
index 000000000..183a99551
--- /dev/null
+++ b/drivers/clocksource/timer-mp-csky.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/sched_clock.h>
+#include <linux/cpu.h>
+#include <linux/of_irq.h>
+#include <asm/reg_ops.h>
+
+#include "timer-of.h"
+
+#define PTIM_CCVR	"cr<3, 14>"
+#define PTIM_CTLR	"cr<0, 14>"
+#define PTIM_LVR	"cr<6, 14>"
+#define PTIM_TSR	"cr<1, 14>"
+
+static int csky_mptimer_irq;
+
+static int csky_mptimer_set_next_event(unsigned long delta,
+				       struct clock_event_device *ce)
+{
+	mtcr(PTIM_LVR, delta);
+
+	return 0;
+}
+
+static int csky_mptimer_shutdown(struct clock_event_device *ce)
+{
+	mtcr(PTIM_CTLR, 0);
+
+	return 0;
+}
+
+static int csky_mptimer_oneshot(struct clock_event_device *ce)
+{
+	mtcr(PTIM_CTLR, 1);
+
+	return 0;
+}
+
+static int csky_mptimer_oneshot_stopped(struct clock_event_device *ce)
+{
+	mtcr(PTIM_CTLR, 0);
+
+	return 0;
+}
+
+static DEFINE_PER_CPU(struct timer_of, csky_to) = {
+	.flags					= TIMER_OF_CLOCK,
+	.clkevt = {
+		.rating				= 300,
+		.features			= CLOCK_EVT_FEAT_PERCPU |
+						  CLOCK_EVT_FEAT_ONESHOT,
+		.set_state_shutdown		= csky_mptimer_shutdown,
+		.set_state_oneshot		= csky_mptimer_oneshot,
+		.set_state_oneshot_stopped	= csky_mptimer_oneshot_stopped,
+		.set_next_event			= csky_mptimer_set_next_event,
+	},
+};
+
+static irqreturn_t csky_timer_interrupt(int irq, void *dev)
+{
+	struct timer_of *to = this_cpu_ptr(&csky_to);
+
+	mtcr(PTIM_TSR, 0);
+
+	to->clkevt.event_handler(&to->clkevt);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * clock event for percpu
+ */
+static int csky_mptimer_starting_cpu(unsigned int cpu)
+{
+	struct timer_of *to = per_cpu_ptr(&csky_to, cpu);
+
+	to->clkevt.cpumask = cpumask_of(cpu);
+
+	enable_percpu_irq(csky_mptimer_irq, 0);
+
+	clockevents_config_and_register(&to->clkevt, timer_of_rate(to),
+					2, ULONG_MAX);
+
+	return 0;
+}
+
+static int csky_mptimer_dying_cpu(unsigned int cpu)
+{
+	disable_percpu_irq(csky_mptimer_irq);
+
+	return 0;
+}
+
+/*
+ * clock source
+ */
+static u64 notrace sched_clock_read(void)
+{
+	return (u64)mfcr(PTIM_CCVR);
+}
+
+static u64 clksrc_read(struct clocksource *c)
+{
+	return (u64)mfcr(PTIM_CCVR);
+}
+
+struct clocksource csky_clocksource = {
+	.name	= "csky",
+	.rating	= 400,
+	.mask	= CLOCKSOURCE_MASK(32),
+	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
+	.read	= clksrc_read,
+};
+
+static int __init csky_mptimer_init(struct device_node *np)
+{
+	int ret, cpu, cpu_rollback;
+	struct timer_of *to = NULL;
+
+	/*
+	 * Csky_mptimer is designed for C-SKY SMP multi-processors and
+	 * every core has it's own private irq and regs for clkevt and
+	 * clksrc.
+	 *
+	 * The regs is accessed by cpu instruction: mfcr/mtcr instead of
+	 * mmio map style. So we needn't mmio-address in dts, but we still
+	 * need to give clk and irq number.
+	 *
+	 * We use private irq for the mptimer and irq number is the same
+	 * for every core. So we use request_percpu_irq() in timer_of_init.
+	 */
+	csky_mptimer_irq = irq_of_parse_and_map(np, 0);
+	if (csky_mptimer_irq <= 0)
+		return -EINVAL;
+
+	ret = request_percpu_irq(csky_mptimer_irq, csky_timer_interrupt,
+				 "csky_mp_timer", &csky_to);
+	if (ret)
+		return -EINVAL;
+
+	for_each_possible_cpu(cpu) {
+		to = per_cpu_ptr(&csky_to, cpu);
+		ret = timer_of_init(np, to);
+		if (ret)
+			goto rollback;
+	}
+
+	clocksource_register_hz(&csky_clocksource, timer_of_rate(to));
+	sched_clock_register(sched_clock_read, 32, timer_of_rate(to));
+
+	ret = cpuhp_setup_state(CPUHP_AP_CSKY_TIMER_STARTING,
+				"clockevents/csky/timer:starting",
+				csky_mptimer_starting_cpu,
+				csky_mptimer_dying_cpu);
+	if (ret)
+		return -EINVAL;
+
+	return 0;
+
+rollback:
+	for_each_possible_cpu(cpu_rollback) {
+		if (cpu_rollback == cpu)
+			break;
+
+		to = per_cpu_ptr(&csky_to, cpu_rollback);
+		timer_of_cleanup(to);
+	}
+	return -EINVAL;
+}
+TIMER_OF_DECLARE(csky_mptimer, "csky,mptimer", csky_mptimer_init);