Commit f7bc74e1 authored by Alexander Graf's avatar Alexander Graf Committed by Avi Kivity
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KVM: PPC: Improve split mode 



When in split mode, instruction relocation and data relocation are not equal.

So far we implemented this mode by reserving a special pseudo-VSID for the
two cases and flushing all PTEs when going into split mode, which is slow.

Unfortunately 32bit Linux and Mac OS X use split mode extensively. So to not
slow down things too much, I came up with a different idea: Mark the split
mode with a bit in the VSID and then treat it like any other segment.

This means we can just flush the shadow segment cache, but keep the PTEs
intact. I verified that this works with ppc32 Linux and Mac OS X 10.4
guests and does speed them up.

Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 7fdaec99

arch/powerpc/include/asm/kvm_book3s.h

+4 −5
Original line number Diff line number Diff line
@@ -100,11 +100,10 @@ struct kvmppc_vcpu_book3s { 
#define CONTEXT_GUEST		1

#define CONTEXT_GUEST_END	2



#define VSID_REAL_DR	0x7ffffffffff00000ULL

#define VSID_REAL_IR	0x7fffffffffe00000ULL

#define VSID_SPLIT_MASK	0x7fffffffffe00000ULL

#define VSID_REAL	0x7fffffffffc00000ULL

#define VSID_BAT	0x7fffffffffb00000ULL

#define VSID_REAL	0x1fffffffffc00000ULL

#define VSID_BAT	0x1fffffffffb00000ULL

#define VSID_REAL_DR	0x2000000000000000ULL

#define VSID_REAL_IR	0x4000000000000000ULL

#define VSID_PR		0x8000000000000000ULL



extern void kvmppc_mmu_pte_flush(struct kvm_vcpu *vcpu, ulong ea, ulong ea_mask);

arch/powerpc/kvm/book3s.c

+14 −14
Original line number Diff line number Diff line
@@ -148,16 +148,8 @@ void kvmppc_set_msr(struct kvm_vcpu *vcpu, u64 msr) 
		}

	}



	if (((vcpu->arch.msr & (MSR_IR|MSR_DR)) != (old_msr & (MSR_IR|MSR_DR))) ||

	    (vcpu->arch.msr & MSR_PR) != (old_msr & MSR_PR)) {

		bool dr = (vcpu->arch.msr & MSR_DR) ? true : false;

		bool ir = (vcpu->arch.msr & MSR_IR) ? true : false;



		/* Flush split mode PTEs */

		if (dr != ir)

			kvmppc_mmu_pte_vflush(vcpu, VSID_SPLIT_MASK,

					      VSID_SPLIT_MASK);



	if ((vcpu->arch.msr & (MSR_PR|MSR_IR|MSR_DR)) !=

		   (old_msr & (MSR_PR|MSR_IR|MSR_DR))) {

		kvmppc_mmu_flush_segments(vcpu);

		kvmppc_mmu_map_segment(vcpu, kvmppc_get_pc(vcpu));

	}
@@ -535,6 +527,7 @@ int kvmppc_handle_pagefault(struct kvm_run *run, struct kvm_vcpu *vcpu, 
	bool is_mmio = false;

	bool dr = (vcpu->arch.msr & MSR_DR) ? true : false;

	bool ir = (vcpu->arch.msr & MSR_IR) ? true : false;

	u64 vsid;



	relocated = data ? dr : ir;
@@ -552,13 +545,20 @@ int kvmppc_handle_pagefault(struct kvm_run *run, struct kvm_vcpu *vcpu, 


	switch (vcpu->arch.msr & (MSR_DR|MSR_IR)) {

	case 0:

		pte.vpage |= VSID_REAL;

		pte.vpage |= ((u64)VSID_REAL << (SID_SHIFT - 12));

		break;

	case MSR_DR:

		pte.vpage |= VSID_REAL_DR;

		break;

	case MSR_IR:

		pte.vpage |= VSID_REAL_IR;

		vcpu->arch.mmu.esid_to_vsid(vcpu, eaddr >> SID_SHIFT, &vsid);



		if ((vcpu->arch.msr & (MSR_DR|MSR_IR)) == MSR_DR)

			pte.vpage |= ((u64)VSID_REAL_DR << (SID_SHIFT - 12));

		else

			pte.vpage |= ((u64)VSID_REAL_IR << (SID_SHIFT - 12));

		pte.vpage |= vsid;



		if (vsid == -1)

			page_found = -EINVAL;

		break;

	}

arch/powerpc/kvm/book3s_32_mmu.c

+13 −8
Original line number Diff line number Diff line
@@ -330,30 +330,35 @@ static void kvmppc_mmu_book3s_32_tlbie(struct kvm_vcpu *vcpu, ulong ea, bool lar 
static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,

					     u64 *vsid)

{

	ulong ea = esid << SID_SHIFT;

	struct kvmppc_sr *sr;

	u64 gvsid = esid;



	if (vcpu->arch.msr & (MSR_DR|MSR_IR)) {

		sr = find_sr(to_book3s(vcpu), ea);

		if (sr->valid)

			gvsid = sr->vsid;

	}



	/* In case we only have one of MSR_IR or MSR_DR set, let's put

	   that in the real-mode context (and hope RM doesn't access

	   high memory) */

	switch (vcpu->arch.msr & (MSR_DR|MSR_IR)) {

	case 0:

		*vsid = (VSID_REAL >> 16) | esid;

		*vsid = VSID_REAL | esid;

		break;

	case MSR_IR:

		*vsid = (VSID_REAL_IR >> 16) | esid;

		*vsid = VSID_REAL_IR | gvsid;

		break;

	case MSR_DR:

		*vsid = (VSID_REAL_DR >> 16) | esid;

		*vsid = VSID_REAL_DR | gvsid;

		break;

	case MSR_DR|MSR_IR:

	{

		ulong ea = esid << SID_SHIFT;

		struct kvmppc_sr *sr = find_sr(to_book3s(vcpu), ea);



		if (!sr->valid)

			return -1;



		*vsid = sr->vsid;

		break;

	}

	default:

		BUG();

	}

arch/powerpc/kvm/book3s_64_mmu.c

+15 −12
Original line number Diff line number Diff line
@@ -442,29 +442,32 @@ static void kvmppc_mmu_book3s_64_tlbie(struct kvm_vcpu *vcpu, ulong va, 
static int kvmppc_mmu_book3s_64_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,

					     u64 *vsid)

{

	ulong ea = esid << SID_SHIFT;

	struct kvmppc_slb *slb;

	u64 gvsid = esid;



	if (vcpu->arch.msr & (MSR_DR|MSR_IR)) {

		slb = kvmppc_mmu_book3s_64_find_slbe(to_book3s(vcpu), ea);

		if (slb)

			gvsid = slb->vsid;

	}



	switch (vcpu->arch.msr & (MSR_DR|MSR_IR)) {

	case 0:

		*vsid = (VSID_REAL >> 16) | esid;

		*vsid = VSID_REAL | esid;

		break;

	case MSR_IR:

		*vsid = (VSID_REAL_IR >> 16) | esid;

		*vsid = VSID_REAL_IR | gvsid;

		break;

	case MSR_DR:

		*vsid = (VSID_REAL_DR >> 16) | esid;

		*vsid = VSID_REAL_DR | gvsid;

		break;

	case MSR_DR|MSR_IR:

	{

		ulong ea;

		struct kvmppc_slb *slb;

		ea = esid << SID_SHIFT;

		slb = kvmppc_mmu_book3s_64_find_slbe(to_book3s(vcpu), ea);

		if (slb)

			*vsid = slb->vsid;

		else

		if (!slb)

			return -ENOENT;



		*vsid = gvsid;

		break;

	}

	default:

		BUG();

		break;