KVM: ia64: Drop in SN2 replacement of fast path ITC emulation fault handler

Copy in SN2 RTC based ITC emulation for fast exit. The two versions
have the same size, so a dropin is simpler than patching the branch
instruction to hit the SN2 version.

Signed-off-by: Jes Sorensen <jes@sgi.com>
Acked-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Jes Sorensen 2009-02-25 10:38:55 -06:00 committed by Avi Kivity
parent ce17c64373
commit 0b5d7a2ccb
4 changed files with 71 additions and 5 deletions

View file

@ -580,6 +580,8 @@ struct kvm_vmm_info{
kvm_vmm_entry *vmm_entry;
kvm_tramp_entry *tramp_entry;
unsigned long vmm_ivt;
unsigned long patch_mov_ar;
unsigned long patch_mov_ar_sn2;
};
int kvm_highest_pending_irq(struct kvm_vcpu *vcpu);

View file

@ -1671,8 +1671,37 @@ out:
return 0;
}
/*
* On SN2, the ITC isn't stable, so copy in fast path code to use the
* SN2 RTC, replacing the ITC based default verion.
*/
static void kvm_patch_vmm(struct kvm_vmm_info *vmm_info,
struct module *module)
{
unsigned long new_ar, new_ar_sn2;
unsigned long module_base;
if (!ia64_platform_is("sn2"))
return;
module_base = (unsigned long)module->module_core;
new_ar = kvm_vmm_base + vmm_info->patch_mov_ar - module_base;
new_ar_sn2 = kvm_vmm_base + vmm_info->patch_mov_ar_sn2 - module_base;
printk(KERN_INFO "kvm: Patching ITC emulation to use SGI SN2 RTC "
"as source\n");
/*
* Copy the SN2 version of mov_ar into place. They are both
* the same size, so 6 bundles is sufficient (6 * 0x10).
*/
memcpy((void *)new_ar, (void *)new_ar_sn2, 0x60);
}
static int kvm_relocate_vmm(struct kvm_vmm_info *vmm_info,
struct module *module)
struct module *module)
{
unsigned long module_base;
unsigned long vmm_size;
@ -1694,6 +1723,7 @@ static int kvm_relocate_vmm(struct kvm_vmm_info *vmm_info,
return -EFAULT;
memcpy((void *)kvm_vmm_base, (void *)module_base, vmm_size);
kvm_patch_vmm(vmm_info, module);
kvm_flush_icache(kvm_vmm_base, vmm_size);
/*Recalculate kvm_vmm_info based on new VMM*/

View file

@ -11,6 +11,7 @@
#include <asm/asmmacro.h>
#include <asm/processor.h>
#include <asm/kvm_host.h>
#include "vti.h"
#include "asm-offsets.h"
@ -140,6 +141,35 @@ GLOBAL_ENTRY(kvm_asm_mov_from_ar)
;;
END(kvm_asm_mov_from_ar)
/*
* Special SGI SN2 optimized version of mov_from_ar using the SN2 RTC
* clock as it's source for emulating the ITC. This version will be
* copied on top of the original version if the host is determined to
* be an SN2.
*/
GLOBAL_ENTRY(kvm_asm_mov_from_ar_sn2)
add r18=VMM_VCPU_ITC_OFS_OFFSET, r21
movl r19 = (KVM_VMM_BASE+(1<<KVM_VMM_SHIFT))
add r16=VMM_VCPU_LAST_ITC_OFFSET,r21
extr.u r17=r25,6,7
mov r24=b0
;;
ld8 r18=[r18]
ld8 r19=[r19]
addl r20=@gprel(asm_mov_to_reg),gp
;;
add r19=r19,r18
shladd r17=r17,4,r20
;;
adds r30=kvm_resume_to_guest-asm_mov_to_reg,r20
st8 [r16] = r19
mov b0=r17
br.sptk.few b0
;;
END(kvm_asm_mov_from_ar_sn2)
// mov r1=rr[r3]
GLOBAL_ENTRY(kvm_asm_mov_from_rr)

View file

@ -30,15 +30,19 @@ MODULE_AUTHOR("Intel");
MODULE_LICENSE("GPL");
extern char kvm_ia64_ivt;
extern char kvm_asm_mov_from_ar;
extern char kvm_asm_mov_from_ar_sn2;
extern fpswa_interface_t *vmm_fpswa_interface;
long vmm_sanity = 1;
struct kvm_vmm_info vmm_info = {
.module = THIS_MODULE,
.vmm_entry = vmm_entry,
.tramp_entry = vmm_trampoline,
.vmm_ivt = (unsigned long)&kvm_ia64_ivt,
.module = THIS_MODULE,
.vmm_entry = vmm_entry,
.tramp_entry = vmm_trampoline,
.vmm_ivt = (unsigned long)&kvm_ia64_ivt,
.patch_mov_ar = (unsigned long)&kvm_asm_mov_from_ar,
.patch_mov_ar_sn2 = (unsigned long)&kvm_asm_mov_from_ar_sn2,
};
static int __init kvm_vmm_init(void)