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, 165 insertions, 0 deletions

diff --git a/scripts/Makefile.host b/scripts/Makefile.host
new file mode 100644
index 000000000..c1dedf646
--- /dev/null
+++ b/scripts/Makefile.host
@@ -0,0 +1,165 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# LEX
+# ---------------------------------------------------------------------------
+quiet_cmd_flex = LEX     $@
+      cmd_flex = $(LEX) -o$@ -L $<
+
+$(obj)/%.lex.c: $(src)/%.l FORCE
+	$(call if_changed,flex)
+
+# YACC
+# ---------------------------------------------------------------------------
+quiet_cmd_bison = YACC    $(basename $@).[ch]
+      cmd_bison = $(YACC) -o $(basename $@).c --defines=$(basename $@).h -t -l $<
+
+$(obj)/%.tab.c $(obj)/%.tab.h: $(src)/%.y FORCE
+	$(call if_changed,bison)
+
+# ==========================================================================
+# Building binaries on the host system
+# Binaries are used during the compilation of the kernel, for example
+# to preprocess a data file.
+#
+# Both C and C++ are supported, but preferred language is C for such utilities.
+# Rust is also supported, but it may only be used in scenarios where a Rust
+# toolchain is required to be available (e.g. when  `CONFIG_RUST` is enabled).
+#
+# Sample syntax (see Documentation/kbuild/makefiles.rst for reference)
+# hostprogs := bin2hex
+# Will compile bin2hex.c and create an executable named bin2hex
+#
+# hostprogs     := lxdialog
+# lxdialog-objs := checklist.o lxdialog.o
+# Will compile lxdialog.c and checklist.c, and then link the executable
+# lxdialog, based on checklist.o and lxdialog.o
+#
+# hostprogs       := qconf
+# qconf-cxxobjs   := qconf.o
+# qconf-objs      := menu.o
+# Will compile qconf as a C++ program, and menu as a C program.
+# They are linked as C++ code to the executable qconf
+#
+# hostprogs   := target
+# target-rust := y
+# Will compile `target` as a Rust program, using `target.rs` as the crate root.
+# The crate may consist of several source files.
+
+# C code
+# Executables compiled from a single .c file
+host-csingle	:= $(foreach m,$(hostprogs), \
+			$(if $($(m)-objs)$($(m)-cxxobjs)$($(m)-rust),,$(m)))
+
+# C executables linked based on several .o files
+host-cmulti	:= $(foreach m,$(hostprogs),\
+		   $(if $($(m)-cxxobjs)$($(m)-rust),,$(if $($(m)-objs),$(m))))
+
+# Object (.o) files compiled from .c files
+host-cobjs	:= $(sort $(foreach m,$(hostprogs),$($(m)-objs)))
+
+# C++ code
+# C++ executables compiled from at least one .cc file
+# and zero or more .c files
+host-cxxmulti	:= $(foreach m,$(hostprogs),$(if $($(m)-cxxobjs),$(m)))
+
+# C++ Object (.o) files compiled from .cc files
+host-cxxobjs	:= $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs)))
+
+# Rust code
+# Executables compiled from a single Rust crate (which may consist of
+# one or more .rs files)
+host-rust	:= $(foreach m,$(hostprogs),$(if $($(m)-rust),$(m)))
+
+host-csingle	:= $(addprefix $(obj)/,$(host-csingle))
+host-cmulti	:= $(addprefix $(obj)/,$(host-cmulti))
+host-cobjs	:= $(addprefix $(obj)/,$(host-cobjs))
+host-cxxmulti	:= $(addprefix $(obj)/,$(host-cxxmulti))
+host-cxxobjs	:= $(addprefix $(obj)/,$(host-cxxobjs))
+host-rust	:= $(addprefix $(obj)/,$(host-rust))
+
+#####
+# Handle options to gcc. Support building with separate output directory
+
+hostc_flags    = -Wp,-MMD,$(depfile) \
+                 $(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS) \
+                 $(HOSTCFLAGS_$(target-stem).o)
+hostcxx_flags  = -Wp,-MMD,$(depfile) \
+                 $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
+                 $(HOSTCXXFLAGS_$(target-stem).o)
+
+# `--out-dir` is required to avoid temporaries being created by `rustc` in the
+# current working directory, which may be not accessible in the out-of-tree
+# modules case.
+hostrust_flags = --out-dir $(dir $@) --emit=dep-info=$(depfile) \
+		 -Clinker-flavor=gcc -Clinker=$(HOSTCC) \
+		 -Clink-args='$(call escsq,$(KBUILD_HOSTLDFLAGS))' \
+                 $(KBUILD_HOSTRUSTFLAGS) $(HOST_EXTRARUSTFLAGS) \
+                 $(HOSTRUSTFLAGS_$(target-stem))
+
+# $(obj) for including generated headers from checkin source files
+ifdef building_out_of_srctree
+hostc_flags   += -I $(obj)
+hostcxx_flags += -I $(obj)
+endif
+
+#####
+# Compile programs on the host
+
+# Create executable from a single .c file
+# host-csingle -> Executable
+quiet_cmd_host-csingle 	= HOSTCC  $@
+      cmd_host-csingle	= $(HOSTCC) $(hostc_flags) $(KBUILD_HOSTLDFLAGS) -o $@ $< \
+		$(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
+$(host-csingle): $(obj)/%: $(obj)/%.c FORCE
+	$(call if_changed_dep,host-csingle)
+
+# Link an executable based on list of .o files, all plain c
+# host-cmulti -> executable
+quiet_cmd_host-cmulti	= HOSTLD  $@
+      cmd_host-cmulti	= $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -o $@ \
+			  $(addprefix $(obj)/, $($(target-stem)-objs)) \
+			  $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
+$(host-cmulti): FORCE
+	$(call if_changed,host-cmulti)
+$(call multi_depend, $(host-cmulti), , -objs)
+
+# Create .o file from a single .c file
+# host-cobjs -> .o
+quiet_cmd_host-cobjs	= HOSTCC  $@
+      cmd_host-cobjs	= $(HOSTCC) $(hostc_flags) -c -o $@ $<
+$(host-cobjs): $(obj)/%.o: $(obj)/%.c FORCE
+	$(call if_changed_dep,host-cobjs)
+
+# Link an executable based on list of .o files, a mixture of .c and .cc
+# host-cxxmulti -> executable
+quiet_cmd_host-cxxmulti	= HOSTLD  $@
+      cmd_host-cxxmulti	= $(HOSTCXX) $(KBUILD_HOSTLDFLAGS) -o $@ \
+			  $(foreach o,objs cxxobjs,\
+			  $(addprefix $(obj)/, $($(target-stem)-$(o)))) \
+			  $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
+$(host-cxxmulti): FORCE
+	$(call if_changed,host-cxxmulti)
+$(call multi_depend, $(host-cxxmulti), , -objs -cxxobjs)
+
+# Create .o file from a single .cc (C++) file
+quiet_cmd_host-cxxobjs	= HOSTCXX $@
+      cmd_host-cxxobjs	= $(HOSTCXX) $(hostcxx_flags) -c -o $@ $<
+$(host-cxxobjs): $(obj)/%.o: $(obj)/%.cc FORCE
+	$(call if_changed_dep,host-cxxobjs)
+
+# Create executable from a single Rust crate (which may consist of
+# one or more `.rs` files)
+# host-rust -> Executable
+quiet_cmd_host-rust	= HOSTRUSTC $@
+      cmd_host-rust	= \
+	$(HOSTRUSTC) $(hostrust_flags) --emit=link=$@ $<
+$(host-rust): $(obj)/%: $(src)/%.rs FORCE
+	+$(call if_changed_dep,host-rust)
+
+targets += $(host-csingle) $(host-cmulti) $(host-cobjs) \
+	   $(host-cxxmulti) $(host-cxxobjs) $(host-rust)
+
+# %.lex.o <- %.lex.c <- %.l
+# %.tab.o <- %.tab.[ch] <- %.y
+targets += $(call intermediate_targets, .lex.o, .lex.c) \
+           $(call intermediate_targets, .tab.o, .tab.c .tab.h)