Merge tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - Support for optimized routines based on the host CPU

 - Support for PCI via virtio

 - Various fixes

* tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: remove unneeded semicolon in um_arch.c
  um: Remove the repeated declaration
  um: fix error return code in winch_tramp()
  um: fix error return code in slip_open()
  um: Fix stack pointer alignment
  um: implement flush_cache_vmap/flush_cache_vunmap
  um: add a UML specific futex implementation
  um: enable the use of optimized xor routines in UML
  um: Add support for host CPU flags and alignment
  um: allow not setting extra rpaths in the linux binary
  um: virtio/pci: enable suspend/resume
  um: add PCI over virtio emulation driver
  um: irqs: allow invoking time-travel handler multiple times
  um: time-travel/signals: fix ndelay() in interrupt
  um: expose time-travel mode to userspace side
  um: export signals_enabled directly
  um: remove unused smp_sigio_handler() declaration
  lib: add iomem emulation (logic_iomem)
  um: allow disabling NO_IOMEM

Author: torvalds

arch/um/Kconfig

@@ -15,7 +15,7 @@ config UML
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DEBUG_BUGVERBOSE
-	select NO_DMA
+	select NO_DMA if !UML_DMA_EMULATION
 	select GENERIC_IRQ_SHOW
 	select GENERIC_CPU_DEVICES
 	select HAVE_GCC_PLUGINS
@@ -26,7 +26,22 @@ config MMU
 	bool
 	default y
 
+config UML_DMA_EMULATION
+	bool
+
 config NO_IOMEM
+	bool "disable IOMEM" if EXPERT
+	depends on !INDIRECT_IOMEM
+	default y
+
+config UML_IOMEM_EMULATION
+	bool
+	select INDIRECT_IOMEM
+	select GENERIC_PCI_IOMAP
+	select GENERIC_IOMAP
+	select NO_GENERIC_PCI_IOPORT_MAP
+
+config NO_IOPORT_MAP
 	def_bool y
 
 config ISA
@@ -61,6 +76,9 @@ config NR_CPUS
 	range 1 1
 	default 1
 
+config ARCH_HAS_CACHE_LINE_SIZE
+	def_bool y
+
 source "arch/$(HEADER_ARCH)/um/Kconfig"
 
 config MAY_HAVE_RUNTIME_DEPS
@@ -91,6 +109,19 @@ config LD_SCRIPT_DYN
 	depends on !LD_SCRIPT_STATIC
 	select MODULE_REL_CRCS if MODVERSIONS
 
+config LD_SCRIPT_DYN_RPATH
+	bool "set rpath in the binary" if EXPERT
+	default y
+	depends on LD_SCRIPT_DYN
+	help
+	  Add /lib (and /lib64 for 64-bit) to the linux binary's rpath
+	  explicitly.
+
+	  You may need to turn this off if compiling for nix systems
+	  that have their libraries in random /nix directories and
+	  might otherwise unexpected use libraries from /lib or /lib64
+	  instead of the desired ones.
+
 config HOSTFS
 	tristate "Host filesystem"
 	help

arch/um/Makefile

@@ -118,7 +118,8 @@ archprepare:
 	$(Q)$(MAKE) $(build)=$(HOST_DIR)/um include/generated/user_constants.h
 
 LINK-$(CONFIG_LD_SCRIPT_STATIC) += -static
-LINK-$(CONFIG_LD_SCRIPT_DYN) += -Wl,-rpath,/lib $(call cc-option, -no-pie)
+LINK-$(CONFIG_LD_SCRIPT_DYN) += $(call cc-option, -no-pie)
+LINK-$(CONFIG_LD_SCRIPT_DYN_RPATH) += -Wl,-rpath,/lib
 
 CFLAGS_NO_HARDENING := $(call cc-option, -fno-PIC,) $(call cc-option, -fno-pic,) \
 	-fno-stack-protector $(call cc-option, -fno-stack-protector-all)

arch/um/drivers/Kconfig

@@ -357,3 +357,23 @@ config UML_RTC
 	  rtcwake, especially in time-travel mode. This driver enables that
 	  by providing a fake RTC clock that causes a wakeup at the right
 	  time.
+
+config UML_PCI_OVER_VIRTIO
+	bool "Enable PCI over VIRTIO device simulation"
+	# in theory, just VIRTIO is enough, but that causes recursion
+	depends on VIRTIO_UML
+	select FORCE_PCI
+	select UML_IOMEM_EMULATION
+	select UML_DMA_EMULATION
+	select PCI_MSI
+	select PCI_MSI_IRQ_DOMAIN
+	select PCI_LOCKLESS_CONFIG
+
+config UML_PCI_OVER_VIRTIO_DEVICE_ID
+	int "set the virtio device ID for PCI emulation"
+	default -1
+	depends on UML_PCI_OVER_VIRTIO
+	help
+	  There's no official device ID assigned (yet), set the one you
+	  wish to use for experimentation here. The default of -1 is
+	  not valid and will cause the driver to fail at probe.

arch/um/drivers/Makefile

@@ -64,6 +64,7 @@ obj-$(CONFIG_BLK_DEV_COW_COMMON) += cow_user.o
 obj-$(CONFIG_UML_RANDOM) += random.o
 obj-$(CONFIG_VIRTIO_UML) += virtio_uml.o
 obj-$(CONFIG_UML_RTC) += rtc.o
+obj-$(CONFIG_UML_PCI_OVER_VIRTIO) += virt-pci.o
 
 # pcap_user.o must be added explicitly.
 USER_OBJS := fd.o null.o pty.o tty.o xterm.o slip_common.o pcap_user.o vde_user.o vector_user.o

arch/um/drivers/chan_user.c

@@ -256,7 +256,8 @@ static int winch_tramp(int fd, struct tty_port *port, int *fd_out,
 		goto out_close;
 	}
 
-	if (os_set_fd_block(*fd_out, 0)) {
+	err = os_set_fd_block(*fd_out, 0);
+	if (err) {
 		printk(UM_KERN_ERR "winch_tramp: failed to set thread_fd "
 		       "non-blocking.\n");
 		goto out_close;

arch/um/drivers/slip_user.c

@@ -145,7 +145,8 @@ static int slip_open(void *data)
 	}
 	sfd = err;
 
-	if (set_up_tty(sfd))
+	err = set_up_tty(sfd);
+	if (err)
 		goto out_close2;
 
 	pri->slave = sfd;

arch/um/drivers/ubd_kern.c

@@ -1242,8 +1242,7 @@ static int __init ubd_driver_init(void){
 		 * enough. So use anyway the io thread. */
 	}
 	stack = alloc_stack(0, 0);
-	io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *),
-				 &thread_fd);
+	io_pid = start_io_thread(stack + PAGE_SIZE, &thread_fd);
 	if(io_pid < 0){
 		printk(KERN_ERR
 		       "ubd : Failed to start I/O thread (errno = %d) - "