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kvm/ppc/e500: eliminate tlb_refs
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Commit 523f0e5 ("KVM: PPC: E500:
Explicitly mark shadow maps invalid") began using E500_TLB_VALID
for guest TLB1 entries, and skipping invalidations if it's not set.

However, when E500_TLB_VALID was set for such entries, it was on a
fake local ref, and so the invalidations never happen.  gtlb_privs
is documented as being only for guest TLB0, though we already violate
that with E500_TLB_BITMAP.

Now that we have MMU notifiers, and thus don't need to actually
retain a reference to the mapped pages, get rid of tlb_refs, and
use gtlb_privs for E500_TLB_VALID in TLB1.

Since we can have more than one host TLB entry for a given tlbe_ref,
be careful not to clear existing flags that are relevant to other
host TLB entries when preparing a new host TLB entry.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
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Scott Wood authored and Alexander Graf committed Apr 11, 2013
1 parent 66a5fec commit 4d2be6f
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Showing 2 changed files with 30 additions and 69 deletions.
24 changes: 8 additions & 16 deletions arch/powerpc/kvm/e500.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -26,17 +26,20 @@
#define E500_PID_NUM 3
#define E500_TLB_NUM 2

#define E500_TLB_VALID 1
#define E500_TLB_BITMAP 2
/* entry is mapped somewhere in host TLB */
#define E500_TLB_VALID (1 << 0)
/* TLB1 entry is mapped by host TLB1, tracked by bitmaps */
#define E500_TLB_BITMAP (1 << 1)
/* TLB1 entry is mapped by host TLB0 */
#define E500_TLB_TLB0 (1 << 2)

struct tlbe_ref {
pfn_t pfn;
unsigned int flags; /* E500_TLB_* */
pfn_t pfn; /* valid only for TLB0, except briefly */
unsigned int flags; /* E500_TLB_* */
};

struct tlbe_priv {
struct tlbe_ref ref; /* TLB0 only -- TLB1 uses tlb_refs */
struct tlbe_ref ref;
};

#ifdef CONFIG_KVM_E500V2
Expand All @@ -63,17 +66,6 @@ struct kvmppc_vcpu_e500 {

unsigned int gtlb_nv[E500_TLB_NUM];

/*
* information associated with each host TLB entry --
* TLB1 only for now. If/when guest TLB1 entries can be
* mapped with host TLB0, this will be used for that too.
*
* We don't want to use this for guest TLB0 because then we'd
* have the overhead of doing the translation again even if
* the entry is still in the guest TLB (e.g. we swapped out
* and back, and our host TLB entries got evicted).
*/
struct tlbe_ref *tlb_refs[E500_TLB_NUM];
unsigned int host_tlb1_nv;

u32 svr;
Expand Down
75 changes: 22 additions & 53 deletions arch/powerpc/kvm/e500_mmu_host.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -193,8 +193,11 @@ void inval_gtlbe_on_host(struct kvmppc_vcpu_e500 *vcpu_e500, int tlbsel,
struct tlbe_ref *ref = &vcpu_e500->gtlb_priv[tlbsel][esel].ref;

/* Don't bother with unmapped entries */
if (!(ref->flags & E500_TLB_VALID))
return;
if (!(ref->flags & E500_TLB_VALID)) {
WARN(ref->flags & (E500_TLB_BITMAP | E500_TLB_TLB0),
"%s: flags %x\n", __func__, ref->flags);
WARN_ON(tlbsel == 1 && vcpu_e500->g2h_tlb1_map[esel]);
}

if (tlbsel == 1 && ref->flags & E500_TLB_BITMAP) {
u64 tmp = vcpu_e500->g2h_tlb1_map[esel];
Expand Down Expand Up @@ -248,7 +251,7 @@ static inline void kvmppc_e500_ref_setup(struct tlbe_ref *ref,
pfn_t pfn)
{
ref->pfn = pfn;
ref->flags = E500_TLB_VALID;
ref->flags |= E500_TLB_VALID;

if (tlbe_is_writable(gtlbe))
kvm_set_pfn_dirty(pfn);
Expand All @@ -257,6 +260,7 @@ static inline void kvmppc_e500_ref_setup(struct tlbe_ref *ref,
static inline void kvmppc_e500_ref_release(struct tlbe_ref *ref)
{
if (ref->flags & E500_TLB_VALID) {
/* FIXME: don't log bogus pfn for TLB1 */
trace_kvm_booke206_ref_release(ref->pfn, ref->flags);
ref->flags = 0;
}
Expand All @@ -274,36 +278,23 @@ static void clear_tlb1_bitmap(struct kvmppc_vcpu_e500 *vcpu_e500)

static void clear_tlb_privs(struct kvmppc_vcpu_e500 *vcpu_e500)
{
int tlbsel = 0;
int i;

for (i = 0; i < vcpu_e500->gtlb_params[tlbsel].entries; i++) {
struct tlbe_ref *ref =
&vcpu_e500->gtlb_priv[tlbsel][i].ref;
kvmppc_e500_ref_release(ref);
}
}

static void clear_tlb_refs(struct kvmppc_vcpu_e500 *vcpu_e500)
{
int stlbsel = 1;
int tlbsel;
int i;

kvmppc_e500_tlbil_all(vcpu_e500);

for (i = 0; i < host_tlb_params[stlbsel].entries; i++) {
struct tlbe_ref *ref =
&vcpu_e500->tlb_refs[stlbsel][i];
kvmppc_e500_ref_release(ref);
for (tlbsel = 0; tlbsel <= 1; tlbsel++) {
for (i = 0; i < vcpu_e500->gtlb_params[tlbsel].entries; i++) {
struct tlbe_ref *ref =
&vcpu_e500->gtlb_priv[tlbsel][i].ref;
kvmppc_e500_ref_release(ref);
}
}

clear_tlb_privs(vcpu_e500);
}

void kvmppc_core_flush_tlb(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
clear_tlb_refs(vcpu_e500);
kvmppc_e500_tlbil_all(vcpu_e500);
clear_tlb_privs(vcpu_e500);
clear_tlb1_bitmap(vcpu_e500);
}

Expand Down Expand Up @@ -458,8 +449,6 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
gvaddr &= ~((tsize_pages << PAGE_SHIFT) - 1);
}

/* Drop old ref and setup new one. */
kvmppc_e500_ref_release(ref);
kvmppc_e500_ref_setup(ref, gtlbe, pfn);

kvmppc_e500_setup_stlbe(&vcpu_e500->vcpu, gtlbe, tsize,
Expand Down Expand Up @@ -512,10 +501,10 @@ static int kvmppc_e500_tlb1_map_tlb1(struct kvmppc_vcpu_e500 *vcpu_e500,
vcpu_e500->g2h_tlb1_map[idx] &= ~(1ULL << sesel);
}

vcpu_e500->tlb_refs[1][sesel] = *ref;
vcpu_e500->gtlb_priv[1][esel].ref.flags |= E500_TLB_BITMAP;
vcpu_e500->g2h_tlb1_map[esel] |= (u64)1 << sesel;
vcpu_e500->h2g_tlb1_rmap[sesel] = esel + 1;
WARN_ON(!(ref->flags & E500_TLB_VALID));

return sesel;
}
Expand All @@ -527,13 +516,12 @@ static int kvmppc_e500_tlb1_map(struct kvmppc_vcpu_e500 *vcpu_e500,
u64 gvaddr, gfn_t gfn, struct kvm_book3e_206_tlb_entry *gtlbe,
struct kvm_book3e_206_tlb_entry *stlbe, int esel)
{
struct tlbe_ref ref;
struct tlbe_ref *ref = &vcpu_e500->gtlb_priv[1][esel].ref;
int sesel;
int r;

ref.flags = 0;
r = kvmppc_e500_shadow_map(vcpu_e500, gvaddr, gfn, gtlbe, 1, stlbe,
&ref);
ref);
if (r)
return r;

Expand All @@ -545,7 +533,7 @@ static int kvmppc_e500_tlb1_map(struct kvmppc_vcpu_e500 *vcpu_e500,
}

/* Otherwise map into TLB1 */
sesel = kvmppc_e500_tlb1_map_tlb1(vcpu_e500, &ref, esel);
sesel = kvmppc_e500_tlb1_map_tlb1(vcpu_e500, ref, esel);
write_stlbe(vcpu_e500, gtlbe, stlbe, 1, sesel);

return 0;
Expand All @@ -566,7 +554,7 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 eaddr, gpa_t gpaddr,
case 0:
priv = &vcpu_e500->gtlb_priv[tlbsel][esel];

/* Triggers after clear_tlb_refs or on initial mapping */
/* Triggers after clear_tlb_privs or on initial mapping */
if (!(priv->ref.flags & E500_TLB_VALID)) {
kvmppc_e500_tlb0_map(vcpu_e500, esel, &stlbe);
} else {
Expand Down Expand Up @@ -666,35 +654,16 @@ int e500_mmu_host_init(struct kvmppc_vcpu_e500 *vcpu_e500)
host_tlb_params[0].entries / host_tlb_params[0].ways;
host_tlb_params[1].sets = 1;

vcpu_e500->tlb_refs[0] =
kzalloc(sizeof(struct tlbe_ref) * host_tlb_params[0].entries,
GFP_KERNEL);
if (!vcpu_e500->tlb_refs[0])
goto err;

vcpu_e500->tlb_refs[1] =
kzalloc(sizeof(struct tlbe_ref) * host_tlb_params[1].entries,
GFP_KERNEL);
if (!vcpu_e500->tlb_refs[1])
goto err;

vcpu_e500->h2g_tlb1_rmap = kzalloc(sizeof(unsigned int) *
host_tlb_params[1].entries,
GFP_KERNEL);
if (!vcpu_e500->h2g_tlb1_rmap)
goto err;
return -EINVAL;

return 0;

err:
kfree(vcpu_e500->tlb_refs[0]);
kfree(vcpu_e500->tlb_refs[1]);
return -EINVAL;
}

void e500_mmu_host_uninit(struct kvmppc_vcpu_e500 *vcpu_e500)
{
kfree(vcpu_e500->h2g_tlb1_rmap);
kfree(vcpu_e500->tlb_refs[0]);
kfree(vcpu_e500->tlb_refs[1]);
}

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