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Commit 468a12c2 authored by Alexander Graf's avatar Alexander Graf Committed by Avi Kivity
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KVM: PPC: Use get/set for to_svcpu to help preemption 



When running the 64-bit Book3s PR code without CONFIG_PREEMPT_NONE, we were
doing a few things wrong, most notably access to PACA fields without making
sure that the pointers stay stable accross the access (preempt_disable()).

This patch moves to_svcpu towards a get/put model which allows us to disable
preemption while accessing the shadow vcpu fields in the PACA. That way we
can run preemptible and everyone's happy!

Reported-by: default avatarJörg Sommer <joerg@alea.gnuu.de>
Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent d33ad328

arch/powerpc/include/asm/kvm_book3s.h

+59 −17
Original line number Diff line number Diff line
@@ -183,7 +183,9 @@ static inline void kvmppc_update_int_pending(struct kvm_vcpu *vcpu, 
static inline void kvmppc_set_gpr(struct kvm_vcpu *vcpu, int num, ulong val)

{

	if ( num < 14 ) {

		to_svcpu(vcpu)->gpr[num] = val;

		struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

		svcpu->gpr[num] = val;

		svcpu_put(svcpu);

		to_book3s(vcpu)->shadow_vcpu->gpr[num] = val;

	} else

		vcpu->arch.gpr[num] = val;
@@ -191,80 +193,120 @@ static inline void kvmppc_set_gpr(struct kvm_vcpu *vcpu, int num, ulong val) 


static inline ulong kvmppc_get_gpr(struct kvm_vcpu *vcpu, int num)

{

	if ( num < 14 )

		return to_svcpu(vcpu)->gpr[num];

	else

	if ( num < 14 ) {

		struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

		ulong r = svcpu->gpr[num];

		svcpu_put(svcpu);

		return r;

	} else

		return vcpu->arch.gpr[num];

}



static inline void kvmppc_set_cr(struct kvm_vcpu *vcpu, u32 val)

{

	to_svcpu(vcpu)->cr = val;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	svcpu->cr = val;

	svcpu_put(svcpu);

	to_book3s(vcpu)->shadow_vcpu->cr = val;

}



static inline u32 kvmppc_get_cr(struct kvm_vcpu *vcpu)

{

	return to_svcpu(vcpu)->cr;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	u32 r;

	r = svcpu->cr;

	svcpu_put(svcpu);

	return r;

}



static inline void kvmppc_set_xer(struct kvm_vcpu *vcpu, u32 val)

{

	to_svcpu(vcpu)->xer = val;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	svcpu->xer = val;

	to_book3s(vcpu)->shadow_vcpu->xer = val;

	svcpu_put(svcpu);

}



static inline u32 kvmppc_get_xer(struct kvm_vcpu *vcpu)

{

	return to_svcpu(vcpu)->xer;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	u32 r;

	r = svcpu->xer;

	svcpu_put(svcpu);

	return r;

}



static inline void kvmppc_set_ctr(struct kvm_vcpu *vcpu, ulong val)

{

	to_svcpu(vcpu)->ctr = val;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	svcpu->ctr = val;

	svcpu_put(svcpu);

}



static inline ulong kvmppc_get_ctr(struct kvm_vcpu *vcpu)

{

	return to_svcpu(vcpu)->ctr;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	ulong r;

	r = svcpu->ctr;

	svcpu_put(svcpu);

	return r;

}



static inline void kvmppc_set_lr(struct kvm_vcpu *vcpu, ulong val)

{

	to_svcpu(vcpu)->lr = val;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	svcpu->lr = val;

	svcpu_put(svcpu);

}



static inline ulong kvmppc_get_lr(struct kvm_vcpu *vcpu)

{

	return to_svcpu(vcpu)->lr;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	ulong r;

	r = svcpu->lr;

	svcpu_put(svcpu);

	return r;

}



static inline void kvmppc_set_pc(struct kvm_vcpu *vcpu, ulong val)

{

	to_svcpu(vcpu)->pc = val;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	svcpu->pc = val;

	svcpu_put(svcpu);

}



static inline ulong kvmppc_get_pc(struct kvm_vcpu *vcpu)

{

	return to_svcpu(vcpu)->pc;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	ulong r;

	r = svcpu->pc;

	svcpu_put(svcpu);

	return r;

}



static inline u32 kvmppc_get_last_inst(struct kvm_vcpu *vcpu)

{

	ulong pc = kvmppc_get_pc(vcpu);

	struct kvmppc_book3s_shadow_vcpu *svcpu = to_svcpu(vcpu);

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	u32 r;



	/* Load the instruction manually if it failed to do so in the

	 * exit path */

	if (svcpu->last_inst == KVM_INST_FETCH_FAILED)

		kvmppc_ld(vcpu, &pc, sizeof(u32), &svcpu->last_inst, false);



	return svcpu->last_inst;

	r = svcpu->last_inst;

	svcpu_put(svcpu);

	return r;

}



static inline ulong kvmppc_get_fault_dar(struct kvm_vcpu *vcpu)

{

	return to_svcpu(vcpu)->fault_dar;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	ulong r;

	r = svcpu->fault_dar;

	svcpu_put(svcpu);

	return r;

}



static inline bool kvmppc_critical_section(struct kvm_vcpu *vcpu)

arch/powerpc/include/asm/kvm_book3s_32.h

+5 −1
Original line number Diff line number Diff line
@@ -20,11 +20,15 @@ 
#ifndef __ASM_KVM_BOOK3S_32_H__

#define __ASM_KVM_BOOK3S_32_H__



static inline struct kvmppc_book3s_shadow_vcpu *to_svcpu(struct kvm_vcpu *vcpu)

static inline struct kvmppc_book3s_shadow_vcpu *svcpu_get(struct kvm_vcpu *vcpu)

{

	return to_book3s(vcpu)->shadow_vcpu;

}



static inline void svcpu_put(struct kvmppc_book3s_shadow_vcpu *svcpu)

{

}



#define PTE_SIZE	12

#define VSID_ALL	0

#define SR_INVALID	0x00000001	/* VSID 1 should always be unused */

arch/powerpc/include/asm/kvm_book3s_64.h

+7 −1
Original line number Diff line number Diff line
@@ -21,10 +21,16 @@ 
#define __ASM_KVM_BOOK3S_64_H__



#ifdef CONFIG_KVM_BOOK3S_PR

static inline struct kvmppc_book3s_shadow_vcpu *to_svcpu(struct kvm_vcpu *vcpu)

static inline struct kvmppc_book3s_shadow_vcpu *svcpu_get(struct kvm_vcpu *vcpu)

{

	preempt_disable();

	return &get_paca()->shadow_vcpu;

}



static inline void svcpu_put(struct kvmppc_book3s_shadow_vcpu *svcpu)

{

	preempt_enable();

}

#endif



#define SPAPR_TCE_SHIFT		12

arch/powerpc/kvm/book3s_32_mmu_host.c

+15 −6
Original line number Diff line number Diff line
@@ -151,13 +151,15 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte) 
	bool primary = false;

	bool evict = false;

	struct hpte_cache *pte;

	int r = 0;



	/* Get host physical address for gpa */

	hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);

	if (is_error_pfn(hpaddr)) {

		printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n",

				 orig_pte->eaddr);

		return -EINVAL;

		r = -EINVAL;

		goto out;

	}

	hpaddr <<= PAGE_SHIFT;
@@ -249,7 +251,8 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte) 


	kvmppc_mmu_hpte_cache_map(vcpu, pte);



	return 0;

out:

	return r;

}



static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
@@ -297,12 +300,14 @@ int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr) 
	u64 gvsid;

	u32 sr;

	struct kvmppc_sid_map *map;

	struct kvmppc_book3s_shadow_vcpu *svcpu = to_svcpu(vcpu);

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	int r = 0;



	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {

		/* Invalidate an entry */

		svcpu->sr[esid] = SR_INVALID;

		return -ENOENT;

		r = -ENOENT;

		goto out;

	}



	map = find_sid_vsid(vcpu, gvsid);
@@ -315,17 +320,21 @@ int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr) 


	dprintk_sr("MMU: mtsr %d, 0x%x\n", esid, sr);



	return 0;

out:

	svcpu_put(svcpu);

	return r;

}



void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)

{

	int i;

	struct kvmppc_book3s_shadow_vcpu *svcpu = to_svcpu(vcpu);

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);



	dprintk_sr("MMU: flushing all segments (%d)\n", ARRAY_SIZE(svcpu->sr));

	for (i = 0; i < ARRAY_SIZE(svcpu->sr); i++)

		svcpu->sr[i] = SR_INVALID;



	svcpu_put(svcpu);

}



void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)

arch/powerpc/kvm/book3s_64_mmu_host.c

+43 −23
Original line number Diff line number Diff line
@@ -88,12 +88,14 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte) 
	int vflags = 0;

	int attempt = 0;

	struct kvmppc_sid_map *map;

	int r = 0;



	/* Get host physical address for gpa */

	hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);

	if (is_error_pfn(hpaddr)) {

		printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n", orig_pte->eaddr);

		return -EINVAL;

		r = -EINVAL;

		goto out;

	}

	hpaddr <<= PAGE_SHIFT;

	hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
@@ -110,7 +112,8 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte) 
		printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",

				vsid, orig_pte->eaddr);

		WARN_ON(true);

		return -EINVAL;

		r = -EINVAL;

		goto out;

	}



	vsid = map->host_vsid;
@@ -131,8 +134,10 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte) 


	/* In case we tried normal mapping already, let's nuke old entries */

	if (attempt > 1)

		if (ppc_md.hpte_remove(hpteg) < 0)

			return -1;

		if (ppc_md.hpte_remove(hpteg) < 0) {

			r = -1;

			goto out;

		}



	ret = ppc_md.hpte_insert(hpteg, va, hpaddr, rflags, vflags, MMU_PAGE_4K, MMU_SEGSIZE_256M);
@@ -162,7 +167,8 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte) 
		kvmppc_mmu_hpte_cache_map(vcpu, pte);

	}



	return 0;

out:

	return r;

}



static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
@@ -207,25 +213,30 @@ static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid) 


static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)

{

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	int i;

	int max_slb_size = 64;

	int found_inval = -1;

	int r;



	if (!to_svcpu(vcpu)->slb_max)

		to_svcpu(vcpu)->slb_max = 1;

	if (!svcpu->slb_max)

		svcpu->slb_max = 1;



	/* Are we overwriting? */

	for (i = 1; i < to_svcpu(vcpu)->slb_max; i++) {

		if (!(to_svcpu(vcpu)->slb[i].esid & SLB_ESID_V))

	for (i = 1; i < svcpu->slb_max; i++) {

		if (!(svcpu->slb[i].esid & SLB_ESID_V))

			found_inval = i;

		else if ((to_svcpu(vcpu)->slb[i].esid & ESID_MASK) == esid)

			return i;

		else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {

			r = i;

			goto out;

		}

	}



	/* Found a spare entry that was invalidated before */

	if (found_inval > 0)

		return found_inval;

	if (found_inval > 0) {

		r = found_inval;

		goto out;

	}



	/* No spare invalid entry, so create one */
@@ -233,30 +244,35 @@ static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid) 
		max_slb_size = mmu_slb_size;



	/* Overflowing -> purge */

	if ((to_svcpu(vcpu)->slb_max) == max_slb_size)

	if ((svcpu->slb_max) == max_slb_size)

		kvmppc_mmu_flush_segments(vcpu);



	r = to_svcpu(vcpu)->slb_max;

	to_svcpu(vcpu)->slb_max++;

	r = svcpu->slb_max;

	svcpu->slb_max++;



out:

	svcpu_put(svcpu);

	return r;

}



int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)

{

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	u64 esid = eaddr >> SID_SHIFT;

	u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;

	u64 slb_vsid = SLB_VSID_USER;

	u64 gvsid;

	int slb_index;

	struct kvmppc_sid_map *map;

	int r = 0;



	slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);



	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {

		/* Invalidate an entry */

		to_svcpu(vcpu)->slb[slb_index].esid = 0;

		return -ENOENT;

		svcpu->slb[slb_index].esid = 0;

		r = -ENOENT;

		goto out;

	}



	map = find_sid_vsid(vcpu, gvsid);
@@ -269,18 +285,22 @@ int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr) 
	slb_vsid &= ~SLB_VSID_KP;

	slb_esid |= slb_index;



	to_svcpu(vcpu)->slb[slb_index].esid = slb_esid;

	to_svcpu(vcpu)->slb[slb_index].vsid = slb_vsid;

	svcpu->slb[slb_index].esid = slb_esid;

	svcpu->slb[slb_index].vsid = slb_vsid;



	trace_kvm_book3s_slbmte(slb_vsid, slb_esid);



	return 0;

out:

	svcpu_put(svcpu);

	return r;

}



void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)

{

	to_svcpu(vcpu)->slb_max = 1;

	to_svcpu(vcpu)->slb[0].esid = 0;

	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);

	svcpu->slb_max = 1;

	svcpu->slb[0].esid = 0;

	svcpu_put(svcpu);

}



void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)