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, 213 insertions, 0 deletions

diff --git a/drivers/clocksource/timer-zevio.c b/drivers/clocksource/timer-zevio.c
new file mode 100644
index 000000000..9a67b84b3
--- /dev/null
+++ b/drivers/clocksource/timer-zevio.c
@@ -0,0 +1,213 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/drivers/clocksource/zevio-timer.c
+ *
+ *  Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
+ */
+
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/cpumask.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+
+#define IO_CURRENT_VAL	0x00
+#define IO_DIVIDER	0x04
+#define IO_CONTROL	0x08
+
+#define IO_TIMER1	0x00
+#define IO_TIMER2	0x0C
+
+#define IO_MATCH_BEGIN	0x18
+#define IO_MATCH(x)	(IO_MATCH_BEGIN + ((x) << 2))
+
+#define IO_INTR_STS	0x00
+#define IO_INTR_ACK	0x00
+#define IO_INTR_MSK	0x04
+
+#define CNTL_STOP_TIMER	(1 << 4)
+#define CNTL_RUN_TIMER	(0 << 4)
+
+#define CNTL_INC	(1 << 3)
+#define CNTL_DEC	(0 << 3)
+
+#define CNTL_TOZERO	0
+#define CNTL_MATCH(x)	((x) + 1)
+#define CNTL_FOREVER	7
+
+/* There are 6 match registers but we only use one. */
+#define TIMER_MATCH	0
+
+#define TIMER_INTR_MSK	(1 << (TIMER_MATCH))
+#define TIMER_INTR_ALL	0x3F
+
+struct zevio_timer {
+	void __iomem *base;
+	void __iomem *timer1, *timer2;
+	void __iomem *interrupt_regs;
+
+	struct clk *clk;
+	struct clock_event_device clkevt;
+
+	char clocksource_name[64];
+	char clockevent_name[64];
+};
+
+static int zevio_timer_set_event(unsigned long delta,
+				 struct clock_event_device *dev)
+{
+	struct zevio_timer *timer = container_of(dev, struct zevio_timer,
+						 clkevt);
+
+	writel(delta, timer->timer1 + IO_CURRENT_VAL);
+	writel(CNTL_RUN_TIMER | CNTL_DEC | CNTL_MATCH(TIMER_MATCH),
+			timer->timer1 + IO_CONTROL);
+
+	return 0;
+}
+
+static int zevio_timer_shutdown(struct clock_event_device *dev)
+{
+	struct zevio_timer *timer = container_of(dev, struct zevio_timer,
+						 clkevt);
+
+	/* Disable timer interrupts */
+	writel(0, timer->interrupt_regs + IO_INTR_MSK);
+	writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK);
+	/* Stop timer */
+	writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL);
+	return 0;
+}
+
+static int zevio_timer_set_oneshot(struct clock_event_device *dev)
+{
+	struct zevio_timer *timer = container_of(dev, struct zevio_timer,
+						 clkevt);
+
+	/* Enable timer interrupts */
+	writel(TIMER_INTR_MSK, timer->interrupt_regs + IO_INTR_MSK);
+	writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK);
+	return 0;
+}
+
+static irqreturn_t zevio_timer_interrupt(int irq, void *dev_id)
+{
+	struct zevio_timer *timer = dev_id;
+	u32 intr;
+
+	intr = readl(timer->interrupt_regs + IO_INTR_ACK);
+	if (!(intr & TIMER_INTR_MSK))
+		return IRQ_NONE;
+
+	writel(TIMER_INTR_MSK, timer->interrupt_regs + IO_INTR_ACK);
+	writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL);
+
+	if (timer->clkevt.event_handler)
+		timer->clkevt.event_handler(&timer->clkevt);
+
+	return IRQ_HANDLED;
+}
+
+static int __init zevio_timer_add(struct device_node *node)
+{
+	struct zevio_timer *timer;
+	struct resource res;
+	int irqnr, ret;
+
+	timer = kzalloc_obj(*timer);
+	if (!timer)
+		return -ENOMEM;
+
+	timer->base = of_iomap(node, 0);
+	if (!timer->base) {
+		ret = -EINVAL;
+		goto error_free;
+	}
+	timer->timer1 = timer->base + IO_TIMER1;
+	timer->timer2 = timer->base + IO_TIMER2;
+
+	timer->clk = of_clk_get(node, 0);
+	if (IS_ERR(timer->clk)) {
+		ret = PTR_ERR(timer->clk);
+		pr_err("Timer clock not found! (error %d)\n", ret);
+		goto error_unmap;
+	}
+
+	timer->interrupt_regs = of_iomap(node, 1);
+	irqnr = irq_of_parse_and_map(node, 0);
+
+	of_address_to_resource(node, 0, &res);
+	scnprintf(timer->clocksource_name, sizeof(timer->clocksource_name),
+			"%llx.%pOFn_clocksource",
+			(unsigned long long)res.start, node);
+
+	scnprintf(timer->clockevent_name, sizeof(timer->clockevent_name),
+			"%llx.%pOFn_clockevent",
+			(unsigned long long)res.start, node);
+
+	if (timer->interrupt_regs && irqnr) {
+		timer->clkevt.name		= timer->clockevent_name;
+		timer->clkevt.set_next_event	= zevio_timer_set_event;
+		timer->clkevt.set_state_shutdown = zevio_timer_shutdown;
+		timer->clkevt.set_state_oneshot = zevio_timer_set_oneshot;
+		timer->clkevt.tick_resume	= zevio_timer_set_oneshot;
+		timer->clkevt.rating		= 200;
+		timer->clkevt.cpumask		= cpu_possible_mask;
+		timer->clkevt.features		= CLOCK_EVT_FEAT_ONESHOT;
+		timer->clkevt.irq		= irqnr;
+
+		writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL);
+		writel(0, timer->timer1 + IO_DIVIDER);
+
+		/* Start with timer interrupts disabled */
+		writel(0, timer->interrupt_regs + IO_INTR_MSK);
+		writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK);
+
+		/* Interrupt to occur when timer value matches 0 */
+		writel(0, timer->base + IO_MATCH(TIMER_MATCH));
+
+		if (request_irq(irqnr, zevio_timer_interrupt,
+				IRQF_TIMER | IRQF_IRQPOLL,
+				timer->clockevent_name, timer)) {
+			pr_err("%s: request_irq() failed\n",
+			       timer->clockevent_name);
+		}
+
+		clockevents_config_and_register(&timer->clkevt,
+				clk_get_rate(timer->clk), 0x0001, 0xffff);
+		pr_info("Added %s as clockevent\n", timer->clockevent_name);
+	}
+
+	writel(CNTL_STOP_TIMER, timer->timer2 + IO_CONTROL);
+	writel(0, timer->timer2 + IO_CURRENT_VAL);
+	writel(0, timer->timer2 + IO_DIVIDER);
+	writel(CNTL_RUN_TIMER | CNTL_FOREVER | CNTL_INC,
+			timer->timer2 + IO_CONTROL);
+
+	clocksource_mmio_init(timer->timer2 + IO_CURRENT_VAL,
+			timer->clocksource_name,
+			clk_get_rate(timer->clk),
+			200, 16,
+			clocksource_mmio_readw_up);
+
+	pr_info("Added %s as clocksource\n", timer->clocksource_name);
+
+	return 0;
+error_unmap:
+	iounmap(timer->base);
+error_free:
+	kfree(timer);
+	return ret;
+}
+
+static int __init zevio_timer_init(struct device_node *node)
+{
+	return zevio_timer_add(node);
+}
+
+TIMER_OF_DECLARE(zevio_timer, "lsi,zevio-timer", zevio_timer_init);