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Commit 0b5d7a2c authored by Jes Sorensen's avatar Jes Sorensen Committed by Avi Kivity
Browse files

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: default avatarJes Sorensen <jes@sgi.com>
Acked-by: default avatarXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent ce17c643

arch/ia64/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -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);

arch/ia64/kvm/kvm-ia64.c

+31 −1
Original line number Diff line number Diff line
@@ -1671,6 +1671,35 @@ static int vti_cpu_has_kvm_support(void) 
	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)

{
@@ -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*/

arch/ia64/kvm/optvfault.S

+30 −0
Original line number Diff line number Diff line
@@ -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)

arch/ia64/kvm/vmm.c

+8 −4
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ 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;
@@ -39,6 +41,8 @@ struct kvm_vmm_info vmm_info = { 
	.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)