diff options
Diffstat (limited to 'pc-bios/optionrom/kvmvapic.S')
| -rw-r--r-- | pc-bios/optionrom/kvmvapic.S | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/pc-bios/optionrom/kvmvapic.S b/pc-bios/optionrom/kvmvapic.S new file mode 100644 index 0000000000..e1d8f1825b --- /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: |