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Commit 7223b915 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus 

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  lguest: stop using KVM hypercall mechanism
  lguest: workaround cmpxchg8b_emu by ignoring cli in the guest.
parents d471a4b9 091ebf07

arch/x86/include/asm/lguest_hcall.h

+23 −6
Original line number Diff line number Diff line
@@ -28,22 +28,39 @@ 


#ifndef __ASSEMBLY__

#include <asm/hw_irq.h>

#include <asm/kvm_para.h>



/*G:030

 * But first, how does our Guest contact the Host to ask for privileged

 * operations?  There are two ways: the direct way is to make a "hypercall",

 * to make requests of the Host Itself.

 *

 * We use the KVM hypercall mechanism, though completely different hypercall

 * numbers. Seventeen hypercalls are available: the hypercall number is put in

 * the %eax register, and the arguments (when required) are placed in %ebx,

 * %ecx, %edx and %esi.  If a return value makes sense, it's returned in %eax.

 * Our hypercall mechanism uses the highest unused trap code (traps 32 and

 * above are used by real hardware interrupts).  Seventeen hypercalls are

 * available: the hypercall number is put in the %eax register, and the

 * arguments (when required) are placed in %ebx, %ecx, %edx and %esi.

 * If a return value makes sense, it's returned in %eax.

 *

 * Grossly invalid calls result in Sudden Death at the hands of the vengeful

 * Host, rather than returning failure.  This reflects Winston Churchill's

 * definition of a gentleman: "someone who is only rude intentionally".

:*/

 */

static inline unsigned long

hcall(unsigned long call,

      unsigned long arg1, unsigned long arg2, unsigned long arg3,

      unsigned long arg4)

{

	/* "int" is the Intel instruction to trigger a trap. */

	asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)

		     /* The call in %eax (aka "a") might be overwritten */

		     : "=a"(call)

		       /* The arguments are in %eax, %ebx, %ecx, %edx & %esi */

		     : "a"(call), "b"(arg1), "c"(arg2), "d"(arg3), "S"(arg4)

		       /* "memory" means this might write somewhere in memory.

			* This isn't true for all calls, but it's safe to tell

			* gcc that it might happen so it doesn't get clever. */

		     : "memory");

	return call;

}



/* Can't use our min() macro here: needs to be a constant */

#define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)

arch/x86/lguest/boot.c

+30 −31
Original line number Diff line number Diff line
@@ -115,7 +115,7 @@ static void async_hcall(unsigned long call, unsigned long arg1, 
	local_irq_save(flags);

	if (lguest_data.hcall_status[next_call] != 0xFF) {

		/* Table full, so do normal hcall which will flush table. */

		kvm_hypercall4(call, arg1, arg2, arg3, arg4);

		hcall(call, arg1, arg2, arg3, arg4);

	} else {

		lguest_data.hcalls[next_call].arg0 = call;

		lguest_data.hcalls[next_call].arg1 = arg1;
@@ -145,11 +145,10 @@ static void async_hcall(unsigned long call, unsigned long arg1, 
 * So, when we're in lazy mode, we call async_hcall() to store the call for

 * future processing:

 */

static void lazy_hcall1(unsigned long call,

		       unsigned long arg1)

static void lazy_hcall1(unsigned long call, unsigned long arg1)

{

	if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE)

		kvm_hypercall1(call, arg1);

		hcall(call, arg1, 0, 0, 0);

	else

		async_hcall(call, arg1, 0, 0, 0);

}
@@ -160,7 +159,7 @@ static void lazy_hcall2(unsigned long call, 
			unsigned long arg2)

{

	if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE)

		kvm_hypercall2(call, arg1, arg2);

		hcall(call, arg1, arg2, 0, 0);

	else

		async_hcall(call, arg1, arg2, 0, 0);

}
@@ -171,7 +170,7 @@ static void lazy_hcall3(unsigned long call, 
			unsigned long arg3)

{

	if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE)

		kvm_hypercall3(call, arg1, arg2, arg3);

		hcall(call, arg1, arg2, arg3, 0);

	else

		async_hcall(call, arg1, arg2, arg3, 0);

}
@@ -184,7 +183,7 @@ static void lazy_hcall4(unsigned long call, 
			unsigned long arg4)

{

	if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE)

		kvm_hypercall4(call, arg1, arg2, arg3, arg4);

		hcall(call, arg1, arg2, arg3, arg4);

	else

		async_hcall(call, arg1, arg2, arg3, arg4);

}
@@ -196,13 +195,13 @@ static void lazy_hcall4(unsigned long call, 
:*/

static void lguest_leave_lazy_mmu_mode(void)

{

	kvm_hypercall0(LHCALL_FLUSH_ASYNC);

	hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0, 0);

	paravirt_leave_lazy_mmu();

}



static void lguest_end_context_switch(struct task_struct *next)

{

	kvm_hypercall0(LHCALL_FLUSH_ASYNC);

	hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0, 0);

	paravirt_end_context_switch(next);

}
@@ -286,7 +285,7 @@ static void lguest_write_idt_entry(gate_desc *dt, 
	/* Keep the local copy up to date. */

	native_write_idt_entry(dt, entrynum, g);

	/* Tell Host about this new entry. */

	kvm_hypercall3(LHCALL_LOAD_IDT_ENTRY, entrynum, desc[0], desc[1]);

	hcall(LHCALL_LOAD_IDT_ENTRY, entrynum, desc[0], desc[1], 0);

}



/*
@@ -300,7 +299,7 @@ static void lguest_load_idt(const struct desc_ptr *desc) 
	struct desc_struct *idt = (void *)desc->address;



	for (i = 0; i < (desc->size+1)/8; i++)

		kvm_hypercall3(LHCALL_LOAD_IDT_ENTRY, i, idt[i].a, idt[i].b);

		hcall(LHCALL_LOAD_IDT_ENTRY, i, idt[i].a, idt[i].b, 0);

}



/*
@@ -321,7 +320,7 @@ static void lguest_load_gdt(const struct desc_ptr *desc) 
	struct desc_struct *gdt = (void *)desc->address;



	for (i = 0; i < (desc->size+1)/8; i++)

		kvm_hypercall3(LHCALL_LOAD_GDT_ENTRY, i, gdt[i].a, gdt[i].b);

		hcall(LHCALL_LOAD_GDT_ENTRY, i, gdt[i].a, gdt[i].b, 0);

}



/*
@@ -334,8 +333,8 @@ static void lguest_write_gdt_entry(struct desc_struct *dt, int entrynum, 
{

	native_write_gdt_entry(dt, entrynum, desc, type);

	/* Tell Host about this new entry. */

	kvm_hypercall3(LHCALL_LOAD_GDT_ENTRY, entrynum,

		       dt[entrynum].a, dt[entrynum].b);

	hcall(LHCALL_LOAD_GDT_ENTRY, entrynum,

	      dt[entrynum].a, dt[entrynum].b, 0);

}



/*
@@ -931,7 +930,7 @@ static int lguest_clockevent_set_next_event(unsigned long delta, 
	}



	/* Please wake us this far in the future. */

	kvm_hypercall1(LHCALL_SET_CLOCKEVENT, delta);

	hcall(LHCALL_SET_CLOCKEVENT, delta, 0, 0, 0);

	return 0;

}
@@ -942,7 +941,7 @@ static void lguest_clockevent_set_mode(enum clock_event_mode mode, 
	case CLOCK_EVT_MODE_UNUSED:

	case CLOCK_EVT_MODE_SHUTDOWN:

		/* A 0 argument shuts the clock down. */

		kvm_hypercall0(LHCALL_SET_CLOCKEVENT);

		hcall(LHCALL_SET_CLOCKEVENT, 0, 0, 0, 0);

		break;

	case CLOCK_EVT_MODE_ONESHOT:

		/* This is what we expect. */
@@ -1100,7 +1099,7 @@ static void set_lguest_basic_apic_ops(void) 
/* STOP!  Until an interrupt comes in. */

static void lguest_safe_halt(void)

{

	kvm_hypercall0(LHCALL_HALT);

	hcall(LHCALL_HALT, 0, 0, 0, 0);

}



/*
@@ -1112,8 +1111,8 @@ static void lguest_safe_halt(void) 
 */

static void lguest_power_off(void)

{

	kvm_hypercall2(LHCALL_SHUTDOWN, __pa("Power down"),

					LGUEST_SHUTDOWN_POWEROFF);

	hcall(LHCALL_SHUTDOWN, __pa("Power down"),

	      LGUEST_SHUTDOWN_POWEROFF, 0, 0);

}



/*
@@ -1123,7 +1122,7 @@ static void lguest_power_off(void) 
 */

static int lguest_panic(struct notifier_block *nb, unsigned long l, void *p)

{

	kvm_hypercall2(LHCALL_SHUTDOWN, __pa(p), LGUEST_SHUTDOWN_POWEROFF);

	hcall(LHCALL_SHUTDOWN, __pa(p), LGUEST_SHUTDOWN_POWEROFF, 0, 0);

	/* The hcall won't return, but to keep gcc happy, we're "done". */

	return NOTIFY_DONE;

}
@@ -1162,7 +1161,7 @@ static __init int early_put_chars(u32 vtermno, const char *buf, int count) 
		len = sizeof(scratch) - 1;

	scratch[len] = '\0';

	memcpy(scratch, buf, len);

	kvm_hypercall1(LHCALL_NOTIFY, __pa(scratch));

	hcall(LHCALL_NOTIFY, __pa(scratch), 0, 0, 0);



	/* This routine returns the number of bytes actually written. */

	return len;
@@ -1174,7 +1173,7 @@ static __init int early_put_chars(u32 vtermno, const char *buf, int count) 
 */

static void lguest_restart(char *reason)

{

	kvm_hypercall2(LHCALL_SHUTDOWN, __pa(reason), LGUEST_SHUTDOWN_RESTART);

	hcall(LHCALL_SHUTDOWN, __pa(reason), LGUEST_SHUTDOWN_RESTART, 0, 0);

}



/*G:050

arch/x86/lguest/i386_head.S

+1 −1
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ ENTRY(lguest_entry) 
	 */

	movl $LHCALL_LGUEST_INIT, %eax

	movl $lguest_data - __PAGE_OFFSET, %ebx

	.byte 0x0f,0x01,0xc1 /* KVM_HYPERCALL */

	int $LGUEST_TRAP_ENTRY



	/* Set up the initial stack so we can run C code. */

	movl $(init_thread_union+THREAD_SIZE),%esp

drivers/lguest/lguest_device.c

+2 −2
Original line number Diff line number Diff line
@@ -178,7 +178,7 @@ static void set_status(struct virtio_device *vdev, u8 status) 


	/* We set the status. */

	to_lgdev(vdev)->desc->status = status;

	kvm_hypercall1(LHCALL_NOTIFY, (max_pfn << PAGE_SHIFT) + offset);

	hcall(LHCALL_NOTIFY, (max_pfn << PAGE_SHIFT) + offset, 0, 0, 0);

}



static void lg_set_status(struct virtio_device *vdev, u8 status)
@@ -229,7 +229,7 @@ static void lg_notify(struct virtqueue *vq) 
	 */

	struct lguest_vq_info *lvq = vq->priv;



	kvm_hypercall1(LHCALL_NOTIFY, lvq->config.pfn << PAGE_SHIFT);

	hcall(LHCALL_NOTIFY, lvq->config.pfn << PAGE_SHIFT, 0, 0, 0);

}



/* An extern declaration inside a C file is bad form.  Don't do it. */

drivers/lguest/x86/core.c

+12 −0
Original line number Diff line number Diff line
@@ -287,6 +287,18 @@ static int emulate_insn(struct lg_cpu *cpu) 
	/* Decoding x86 instructions is icky. */

	insn = lgread(cpu, physaddr, u8);



	/*

	 * Around 2.6.33, the kernel started using an emulation for the

	 * cmpxchg8b instruction in early boot on many configurations.  This

	 * code isn't paravirtualized, and it tries to disable interrupts.

	 * Ignore it, which will Mostly Work.

	 */

	if (insn == 0xfa) {

		/* "cli", or Clear Interrupt Enable instruction.  Skip it. */

		cpu->regs->eip++;

		return 1;

	}



	/*

	 * 0x66 is an "operand prefix".  It means it's using the upper 16 bits

	 * of the eax register.