Commit b9bb6fb7 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 

Pull virtio updates from Rusty Russell:
 "Some virtio internal cleanups, a new virtio device "virtio input", and
  a change to allow the legacy virtio balloon.

  Most excitingly, some lguest work! No seriously, I got some cleanup
  patches"

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  virtio: drop virtio_device_is_legacy_only
  virtio_pci: support non-legacy balloon devices
  virtio_mmio: support non-legacy balloon devices
  virtio_ccw: support non-legacy balloon devices
  virtio: balloon might not be a legacy device
  virtio_balloon: transitional interface
  virtio_ring: Update weak barriers to use dma_wmb/rmb
  virtio_pci_modern: switch to type-safe io accessors
  virtio_pci_modern: type-safe io accessors
  lguest: handle traps on the "interrupt suppressed" iret instruction.
  virtio: drop a useless config read
  virtio_config: reorder functions
  Add virtio-input driver.
  lguest: suppress interrupts for single insn, not range.
  lguest: simplify lguest_iret
  lguest: rename i386_head.S in the comments
  lguest: explicitly set miscdevice's private_data NULL
  lguest: fix pending interrupt test.
parents 15ce2658 9abbfb48

MAINTAINERS

+6 −0
Original line number Diff line number Diff line
@@ -10517,6 +10517,12 @@ S: Maintained 
F:	drivers/vhost/

F:	include/uapi/linux/vhost.h



VIRTIO INPUT DRIVER

M:	Gerd Hoffmann <kraxel@redhat.com>

S:	Maintained

F:	drivers/virtio/virtio_input.c

F:	include/uapi/linux/virtio_input.h



VIA RHINE NETWORK DRIVER

M:	Roger Luethi <rl@hellgate.ch>

S:	Maintained

arch/x86/include/asm/lguest.h

+2 −5
Original line number Diff line number Diff line
@@ -20,13 +20,10 @@ extern unsigned long switcher_addr; 
/* Found in switcher.S */

extern unsigned long default_idt_entries[];



/* Declarations for definitions in lguest_guest.S */

extern char lguest_noirq_start[], lguest_noirq_end[];

/* Declarations for definitions in arch/x86/lguest/head_32.S */

extern char lguest_noirq_iret[];

extern const char lgstart_cli[], lgend_cli[];

extern const char lgstart_sti[], lgend_sti[];

extern const char lgstart_popf[], lgend_popf[];

extern const char lgstart_pushf[], lgend_pushf[];

extern const char lgstart_iret[], lgend_iret[];



extern void lguest_iret(void);

extern void lguest_init(void);

arch/x86/lguest/boot.c

+3 −4
Original line number Diff line number Diff line
@@ -87,8 +87,7 @@ 


struct lguest_data lguest_data = {

	.hcall_status = { [0 ... LHCALL_RING_SIZE-1] = 0xFF },

	.noirq_start = (u32)lguest_noirq_start,

	.noirq_end = (u32)lguest_noirq_end,

	.noirq_iret = (u32)lguest_noirq_iret,

	.kernel_address = PAGE_OFFSET,

	.blocked_interrupts = { 1 }, /* Block timer interrupts */

	.syscall_vec = SYSCALL_VECTOR,
@@ -262,7 +261,7 @@ PV_CALLEE_SAVE_REGS_THUNK(lguest_save_fl); 
PV_CALLEE_SAVE_REGS_THUNK(lguest_irq_disable);

/*:*/



/* These are in i386_head.S */

/* These are in head_32.S */

extern void lg_irq_enable(void);

extern void lg_restore_fl(unsigned long flags);
@@ -1368,7 +1367,7 @@ static void lguest_restart(char *reason) 
 * fit comfortably.

 *

 * First we need assembly templates of each of the patchable Guest operations,

 * and these are in i386_head.S.

 * and these are in head_32.S.

 */



/*G:060 We construct a table from the assembler templates: */

arch/x86/lguest/head_32.S

+13 −17
Original line number Diff line number Diff line
@@ -84,7 +84,7 @@ ENTRY(lg_irq_enable) 
	 * set lguest_data.irq_pending to X86_EFLAGS_IF.  If it's not zero, we

	 * jump to send_interrupts, otherwise we're done.

	 */

	testl $0, lguest_data+LGUEST_DATA_irq_pending

	cmpl $0, lguest_data+LGUEST_DATA_irq_pending

	jnz send_interrupts

	/*

	 * One cool thing about x86 is that you can do many things without using
@@ -133,9 +133,8 @@ ENTRY(lg_restore_fl) 
	ret

/*:*/



/* These demark the EIP range where host should never deliver interrupts. */

.global lguest_noirq_start

.global lguest_noirq_end

/* These demark the EIP where host should never deliver interrupts. */

.global lguest_noirq_iret



/*M:004

 * When the Host reflects a trap or injects an interrupt into the Guest, it
@@ -168,29 +167,26 @@ ENTRY(lg_restore_fl) 
 * So we have to copy eflags from the stack to lguest_data.irq_enabled before

 * we do the "iret".

 *

 * There are two problems with this: firstly, we need to use a register to do

 * the copy and secondly, the whole thing needs to be atomic.  The first

 * problem is easy to solve: push %eax on the stack so we can use it, and then

 * restore it at the end just before the real "iret".

 * There are two problems with this: firstly, we can't clobber any registers

 * and secondly, the whole thing needs to be atomic.  The first problem

 * is solved by using "push memory"/"pop memory" instruction pair for copying.

 *

 * The second is harder: copying eflags to lguest_data.irq_enabled will turn

 * interrupts on before we're finished, so we could be interrupted before we

 * return to userspace or wherever.  Our solution to this is to surround the

 * code with lguest_noirq_start: and lguest_noirq_end: labels.  We tell the

 * return to userspace or wherever.  Our solution to this is to tell the

 * Host that it is *never* to interrupt us there, even if interrupts seem to be

 * enabled.

 * enabled. (It's not necessary to protect pop instruction, since

 * data gets updated only after it completes, so we only need to protect

 * one instruction, iret).

 */

ENTRY(lguest_iret)

	pushl	%eax

	movl	12(%esp), %eax

lguest_noirq_start:

	pushl	2*4(%esp)

	/*

	 * Note the %ss: segment prefix here.  Normal data accesses use the

	 * "ds" segment, but that will have already been restored for whatever

	 * we're returning to (such as userspace): we can't trust it.  The %ss:

	 * prefix makes sure we use the stack segment, which is still valid.

	 */

	movl	%eax,%ss:lguest_data+LGUEST_DATA_irq_enabled

	popl	%eax

	popl	%ss:lguest_data+LGUEST_DATA_irq_enabled

lguest_noirq_iret:

	iret
 
lguest_noirq_end:

drivers/lguest/hypercalls.c

+2 −3
Original line number Diff line number Diff line
@@ -211,10 +211,9 @@ static void initialize(struct lg_cpu *cpu) 


	/*

	 * The Guest tells us where we're not to deliver interrupts by putting

	 * the range of addresses into "struct lguest_data".

	 * the instruction address into "struct lguest_data".

	 */

	if (get_user(cpu->lg->noirq_start, &cpu->lg->lguest_data->noirq_start)

	    || get_user(cpu->lg->noirq_end, &cpu->lg->lguest_data->noirq_end))

	if (get_user(cpu->lg->noirq_iret, &cpu->lg->lguest_data->noirq_iret))

		kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);



	/*

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