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Commit df08bd10 authored by Alexander Graf's avatar Alexander Graf Committed by Avi Kivity
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KVM: PPC: Make PV mtmsrd L=1 work with r30 and r31 



We had an arbitrary limitation in mtmsrd L=1 that kept us from using r30 and
r31 as input registers. Let's get rid of that and get more potential speedups!

Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
parent 9ee18b1e

arch/powerpc/kernel/kvm.c

+17 −4
Original line number Diff line number Diff line
@@ -158,6 +158,7 @@ static u32 *kvm_alloc(int len) 


extern u32 kvm_emulate_mtmsrd_branch_offs;

extern u32 kvm_emulate_mtmsrd_reg_offs;

extern u32 kvm_emulate_mtmsrd_orig_ins_offs;

extern u32 kvm_emulate_mtmsrd_len;

extern u32 kvm_emulate_mtmsrd[];
@@ -186,7 +187,21 @@ static void kvm_patch_ins_mtmsrd(u32 *inst, u32 rt) 
	/* Modify the chunk to fit the invocation */

	memcpy(p, kvm_emulate_mtmsrd, kvm_emulate_mtmsrd_len * 4);

	p[kvm_emulate_mtmsrd_branch_offs] |= distance_end & KVM_INST_B_MASK;

	switch (get_rt(rt)) {

	case 30:

		kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],

				 magic_var(scratch2), KVM_RT_30);

		break;

	case 31:

		kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],

				 magic_var(scratch1), KVM_RT_30);

		break;

	default:

		p[kvm_emulate_mtmsrd_reg_offs] |= rt;

		break;

	}



	p[kvm_emulate_mtmsrd_orig_ins_offs] = *inst;

	flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsrd_len * 4);



	/* Patch the invocation */
@@ -423,8 +438,6 @@ static void kvm_check_ins(u32 *inst, u32 features) 


	/* Rewrites */

	case KVM_INST_MTMSRD_L1:

		/* We use r30 and r31 during the hook */

		if (get_rt(inst_rt) < 30)

		kvm_patch_ins_mtmsrd(inst, inst_rt);

		break;

	case KVM_INST_MTMSR:

arch/powerpc/kernel/kvm_emul.S

+7 −1
Original line number Diff line number Diff line
@@ -78,7 +78,8 @@ kvm_emulate_mtmsrd: 


	/* OR the register's (MSR_EE|MSR_RI) on MSR */

kvm_emulate_mtmsrd_reg:

	andi.	r30, r0, (MSR_EE|MSR_RI)

	ori	r30, r0, 0

	andi.	r30, r30, (MSR_EE|MSR_RI)

	or	r31, r31, r30



	/* Put MSR back into magic page */
@@ -96,6 +97,7 @@ kvm_emulate_mtmsrd_reg: 
	SCRATCH_RESTORE



	/* Nag hypervisor */

kvm_emulate_mtmsrd_orig_ins:

	tlbsync



	b	kvm_emulate_mtmsrd_branch
@@ -117,6 +119,10 @@ kvm_emulate_mtmsrd_branch_offs: 
kvm_emulate_mtmsrd_reg_offs:

	.long (kvm_emulate_mtmsrd_reg - kvm_emulate_mtmsrd) / 4



.global kvm_emulate_mtmsrd_orig_ins_offs

kvm_emulate_mtmsrd_orig_ins_offs:

	.long (kvm_emulate_mtmsrd_orig_ins - kvm_emulate_mtmsrd) / 4



.global kvm_emulate_mtmsrd_len

kvm_emulate_mtmsrd_len:

	.long (kvm_emulate_mtmsrd_end - kvm_emulate_mtmsrd) / 4