kvmvapic: Add option ROM

This imports and builds the original VAPIC option ROM of qemu-kvm.
Its interaction with QEMU is described in the commit that introduces the
corresponding device model.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

2 files changed, 342 insertions, 1 deletions

diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile
index 2caf7e6..f6b4027 100644
--- a/pc-bios/optionrom/Makefile
+++ b/pc-bios/optionrom/Makefile
@@ -14,7 +14,7 @@ CFLAGS += -I$(SRC_PATH)
 CFLAGS += $(call cc-option, $(CFLAGS), -fno-stack-protector)
 QEMU_CFLAGS = $(CFLAGS)
 
-build-all: multiboot.bin linuxboot.bin
+build-all: multiboot.bin linuxboot.bin kvmvapic.bin
 
 # suppress auto-removal of intermediate files
 .SECONDARY:
diff --git a/pc-bios/optionrom/kvmvapic.S b/pc-bios/optionrom/kvmvapic.S
new file mode 100644
index 0000000..e1d8f18
--- /dev/null
+++ b/pc-bios/optionrom/kvmvapic.S
@@ -0,0 +1,341 @@
+#
+# Local APIC acceleration for Windows XP and related guests
+#
+# Copyright 2011 Red Hat, Inc. and/or its affiliates
+#
+# Author: Avi Kivity <avi@redhat.com>
+#
+# This work is licensed under the terms of the GNU GPL, version 2, or (at your
+# option) any later version.  See the COPYING file in the top-level directory.
+#
+
+	.text 0
+	.code16
+.global _start
+_start:
+	.short 0xaa55
+	.byte (_end - _start) / 512
+	# clear vapic area: firmware load using rep insb may cause
+	# stale tpr/isr/irr data to corrupt the vapic area.
+	push %es
+	push %cs
+	pop %es
+	xor %ax, %ax
+	mov $vapic_size/2, %cx
+	lea vapic, %di
+	cld
+	rep stosw
+	pop %es
+	mov $vapic_base, %ax
+	out %ax, $0x7e
+	lret
+
+	.code32
+vapic_size = 2*4096
+
+.macro fixup delta=-4
+777:
+	.text 1
+	.long 777b + \delta  - vapic_base
+	.text 0
+.endm
+
+.macro reenable_vtpr
+	out %al, $0x7e
+.endm
+
+.text 1
+	fixup_start = .
+.text 0
+
+.align 16
+
+vapic_base:
+	.ascii "kvm aPiC"
+
+	/* relocation data */
+	.long vapic_base	; fixup
+	.long fixup_start	; fixup
+	.long fixup_end		; fixup
+
+	.long vapic		; fixup
+	.long vapic_size
+vcpu_shift:
+	.long 0
+real_tpr:
+	.long 0
+	.long up_set_tpr	; fixup
+	.long up_set_tpr_eax	; fixup
+	.long up_get_tpr_eax	; fixup
+	.long up_get_tpr_ecx	; fixup
+	.long up_get_tpr_edx	; fixup
+	.long up_get_tpr_ebx	; fixup
+	.long 0 /* esp. won't work. */
+	.long up_get_tpr_ebp	; fixup
+	.long up_get_tpr_esi	; fixup
+	.long up_get_tpr_edi	; fixup
+	.long up_get_tpr_stack  ; fixup
+	.long mp_set_tpr	; fixup
+	.long mp_set_tpr_eax	; fixup
+	.long mp_get_tpr_eax	; fixup
+	.long mp_get_tpr_ecx	; fixup
+	.long mp_get_tpr_edx	; fixup
+	.long mp_get_tpr_ebx	; fixup
+	.long 0 /* esp. won't work. */
+	.long mp_get_tpr_ebp	; fixup
+	.long mp_get_tpr_esi	; fixup
+	.long mp_get_tpr_edi	; fixup
+	.long mp_get_tpr_stack  ; fixup
+
+.macro kvm_hypercall
+	.byte 0x0f, 0x01, 0xc1
+.endm
+
+kvm_hypercall_vapic_poll_irq = 1
+
+pcr_cpu = 0x51
+
+.align 64
+
+mp_get_tpr_eax:
+	pushf
+	cli
+	reenable_vtpr
+	push %ecx
+
+	fs/movzbl pcr_cpu, %eax
+
+	mov vcpu_shift, %ecx	; fixup
+	shl %cl, %eax
+	testb $1, vapic+4(%eax)	; fixup delta=-5
+	jz mp_get_tpr_bad
+	movzbl vapic(%eax), %eax ; fixup
+
+mp_get_tpr_out:
+	pop %ecx
+	popf
+	ret
+
+mp_get_tpr_bad:
+	mov real_tpr, %eax	; fixup
+	mov (%eax), %eax
+	jmp mp_get_tpr_out
+
+mp_get_tpr_ebx:
+	mov %eax, %ebx
+	call mp_get_tpr_eax
+	xchg %eax, %ebx
+	ret
+
+mp_get_tpr_ecx:
+	mov %eax, %ecx
+	call mp_get_tpr_eax
+	xchg %eax, %ecx
+	ret
+
+mp_get_tpr_edx:
+	mov %eax, %edx
+	call mp_get_tpr_eax
+	xchg %eax, %edx
+	ret
+
+mp_get_tpr_esi:
+	mov %eax, %esi
+	call mp_get_tpr_eax
+	xchg %eax, %esi
+	ret
+
+mp_get_tpr_edi:
+	mov %eax, %edi
+	call mp_get_tpr_edi
+	xchg %eax, %edi
+	ret
+
+mp_get_tpr_ebp:
+	mov %eax, %ebp
+	call mp_get_tpr_eax
+	xchg %eax, %ebp
+	ret
+
+mp_get_tpr_stack:
+	call mp_get_tpr_eax
+	xchg %eax, 4(%esp)
+	ret
+
+mp_set_tpr_eax:
+	push %eax
+	call mp_set_tpr
+	ret
+
+mp_set_tpr:
+	pushf
+	push %eax
+	push %ecx
+	push %edx
+	push %ebx
+	cli
+	reenable_vtpr
+
+mp_set_tpr_failed:
+	fs/movzbl pcr_cpu, %edx
+
+	mov vcpu_shift, %ecx	; fixup
+	shl %cl, %edx
+
+	testb $1, vapic+4(%edx)	; fixup delta=-5
+	jz mp_set_tpr_bad
+
+	mov vapic(%edx), %eax	; fixup
+
+	mov %eax, %ebx
+	mov 24(%esp), %bl
+
+	/* %ebx = new vapic (%bl = tpr, %bh = isr, %b3 = irr) */
+
+	lock cmpxchg %ebx, vapic(%edx) ; fixup
+	jnz mp_set_tpr_failed
+
+	/* compute ppr */
+	cmp %bh, %bl
+	jae mp_tpr_is_bigger
+mp_isr_is_bigger:
+	mov %bh, %bl
+mp_tpr_is_bigger:
+	/* %bl = ppr */
+	mov %bl, %ch   /* ch = ppr */
+	rol $8, %ebx
+	/* now: %bl = irr, %bh = ppr */
+	cmp %bh, %bl
+	ja mp_set_tpr_poll_irq
+
+mp_set_tpr_out:
+	pop %ebx
+	pop %edx
+	pop %ecx
+	pop %eax
+	popf
+	ret $4
+
+mp_set_tpr_poll_irq:
+	mov $kvm_hypercall_vapic_poll_irq, %eax
+	kvm_hypercall
+	jmp mp_set_tpr_out
+
+mp_set_tpr_bad:
+	mov 24(%esp), %ecx
+	mov real_tpr, %eax	; fixup
+	mov %ecx, (%eax)
+	jmp mp_set_tpr_out
+
+up_get_tpr_eax:
+	reenable_vtpr
+	movzbl vapic, %eax ; fixup
+	ret
+
+up_get_tpr_ebx:
+	reenable_vtpr
+	movzbl vapic, %ebx ; fixup
+	ret
+
+up_get_tpr_ecx:
+	reenable_vtpr
+	movzbl vapic, %ecx ; fixup
+	ret
+
+up_get_tpr_edx:
+	reenable_vtpr
+	movzbl vapic, %edx ; fixup
+	ret
+
+up_get_tpr_esi:
+	reenable_vtpr
+	movzbl vapic, %esi ; fixup
+	ret
+
+up_get_tpr_edi:
+	reenable_vtpr
+	movzbl vapic, %edi ; fixup
+	ret
+
+up_get_tpr_ebp:
+	reenable_vtpr
+	movzbl vapic, %ebp ; fixup
+	ret
+
+up_get_tpr_stack:
+	reenable_vtpr
+	movzbl vapic, %eax ; fixup
+	xchg %eax, 4(%esp)
+	ret
+
+up_set_tpr_eax:
+	push %eax
+	call up_set_tpr
+	ret
+
+up_set_tpr:
+	pushf
+	push %eax
+	push %ecx
+	push %ebx
+	reenable_vtpr
+
+up_set_tpr_failed:
+	mov vapic, %eax	; fixup
+
+	mov %eax, %ebx
+	mov 20(%esp), %bl
+
+	/* %ebx = new vapic (%bl = tpr, %bh = isr, %b3 = irr) */
+
+	lock cmpxchg %ebx, vapic ; fixup
+	jnz up_set_tpr_failed
+
+	/* compute ppr */
+	cmp %bh, %bl
+	jae up_tpr_is_bigger
+up_isr_is_bigger:
+	mov %bh, %bl
+up_tpr_is_bigger:
+	/* %bl = ppr */
+	mov %bl, %ch   /* ch = ppr */
+	rol $8, %ebx
+	/* now: %bl = irr, %bh = ppr */
+	cmp %bh, %bl
+	ja up_set_tpr_poll_irq
+
+up_set_tpr_out:
+	pop %ebx
+	pop %ecx
+	pop %eax
+	popf
+	ret $4
+
+up_set_tpr_poll_irq:
+	mov $kvm_hypercall_vapic_poll_irq, %eax
+	kvm_hypercall
+	jmp up_set_tpr_out
+
+.text 1
+	fixup_end = .
+.text 0
+
+/*
+ * vapic format:
+ *  per-vcpu records of size 2^vcpu shift.
+ *     byte 0: tpr (r/w)
+ *     byte 1: highest in-service interrupt (isr) (r/o); bits 3:0 are zero
+ *     byte 2: zero (r/o)
+ *     byte 3: highest pending interrupt (irr) (r/o)
+ */
+.text 2
+
+.align 128
+
+vapic:
+. = . + vapic_size
+
+.byte 0  # reserve space for signature
+.align 512, 0
+
+_end: