|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v12 5/6] x86/ioreq server: Asynchronously reset outstanding p2m_ioreq_server entries.
>>> On 07.04.17 at 15:56, <george.dunlap@xxxxxxxxxx> wrote:
Most important thing first: The logic looks correct to me now.
> --- a/xen/arch/x86/mm/p2m-ept.c
> +++ b/xen/arch/x86/mm/p2m-ept.c
> @@ -533,6 +533,7 @@ static int resolve_misconfig(struct p2m_domain *p2m,
> unsigned long gfn)
> {
> for ( gfn -= i, i = 0; i < EPT_PAGETABLE_ENTRIES; ++i )
> {
> + p2m_type_t nt;
> e = atomic_read_ept_entry(&epte[i]);
Blank line between these two please.
> @@ -542,10 +543,15 @@ static int resolve_misconfig(struct p2m_domain *p2m,
> unsigned long gfn)
> _mfn(e.mfn), 0, &ipat,
> e.sa_p2mt == p2m_mmio_direct);
> e.ipat = ipat;
> - if ( e.recalc && p2m_is_changeable(e.sa_p2mt) )
> - {
> - e.sa_p2mt = p2m_is_logdirty_range(p2m, gfn + i, gfn
> + i)
> - ? p2m_ram_logdirty : p2m_ram_rw;
> + nt = p2m_recalc_type(e.recalc, e.sa_p2mt, p2m, gfn + i);
> + if ( nt != e.sa_p2mt ) {
Brace on its own line please.
> + if ( e.sa_p2mt == p2m_ioreq_server )
> + {
> + ASSERT(p2m->ioreq.entry_count > 0);
> + p2m->ioreq.entry_count--;
> + }
> +
> + e.sa_p2mt = nt;
> ept_p2m_type_to_flags(p2m, &e, e.sa_p2mt, e.access);
> }
This changes why ept_p2m_type_to_flags() is bypassed. I think
this is correct, but that wasn't immediately clear.
> @@ -562,23 +568,24 @@ static int resolve_misconfig(struct p2m_domain *p2m,
> unsigned long gfn)
>
> if ( recalc && p2m_is_changeable(e.sa_p2mt) )
> {
> - unsigned long mask = ~0UL << (level * EPT_TABLE_ORDER);
> -
> - switch ( p2m_is_logdirty_range(p2m, gfn & mask,
> - gfn | ~mask) )
> - {
> - case 0:
> - e.sa_p2mt = p2m_ram_rw;
> - e.recalc = 0;
> - break;
> - case 1:
> - e.sa_p2mt = p2m_ram_logdirty;
> - e.recalc = 0;
> - break;
> - default: /* Force split. */
> - emt = -1;
> - break;
> - }
> + unsigned long mask = ~0UL << (level * EPT_TABLE_ORDER);
> +
> + ASSERT(e.sa_p2mt != p2m_ioreq_server);
> + switch ( p2m_is_logdirty_range(p2m, gfn & mask,
> + gfn | ~mask) )
> + {
> + case 0:
> + e.sa_p2mt = p2m_ram_rw;
> + e.recalc = 0;
> + break;
> + case 1:
> + e.sa_p2mt = p2m_ram_logdirty;
> + e.recalc = 0;
> + break;
> + default: /* Force split. */
> + emt = -1;
> + break;
> + }
> }
So if I'm getting it right the change here really is just the addition of
an ASSERT() and re-indentation? I think you will want to also adjust
indentation in the previous hunk then. (I'm afraid it was me who
broke it back when introducing that code...)
> @@ -606,6 +616,8 @@ p2m_pt_set_entry(struct p2m_domain *p2m, unsigned long
> gfn, mfn_t mfn,
>
> if ( page_order == PAGE_ORDER_4K )
> {
> + p2m_type_t p2mt_old;
> +
> rc = p2m_next_level(p2m, &table, &gfn_remainder, gfn,
> L2_PAGETABLE_SHIFT - PAGE_SHIFT,
> L2_PAGETABLE_ENTRIES, PGT_l1_page_table, 1);
> @@ -629,6 +641,21 @@ p2m_pt_set_entry(struct p2m_domain *p2m, unsigned long
> gfn, mfn_t mfn,
> if ( entry_content.l1 != 0 )
> p2m_add_iommu_flags(&entry_content, 0, iommu_pte_flags);
>
> + p2mt_old = p2m_flags_to_type(l1e_get_flags(*p2m_entry));
> +
> + /*
> + * p2m_ioreq_server is only used for 4K pages, so
> + * the count shall only be performed for level 1 entries.
> + */
> + if ( p2mt == p2m_ioreq_server )
> + p2m->ioreq.entry_count++;
> +
> + if ( p2mt_old == p2m_ioreq_server )
> + {
> + ASSERT(p2m->ioreq.entry_count > 0);
> + p2m->ioreq.entry_count--;
> + }
> +
> /* level 1 entry */
> p2m->write_p2m_entry(p2m, gfn, p2m_entry, entry_content, 1);
> /* NB: paging_write_p2m_entry() handles tlb flushes properly */
> @@ -726,15 +753,6 @@ p2m_pt_set_entry(struct p2m_domain *p2m, unsigned long
> gfn, mfn_t mfn,
> return rc;
> }
I would have hoped for the two ASSERT()s to be added for the
2M and 1G cases, which we did talk about.
> --- a/xen/include/asm-x86/p2m.h
> +++ b/xen/include/asm-x86/p2m.h
> @@ -120,7 +120,10 @@ typedef unsigned int p2m_query_t;
>
> /* Types that can be subject to bulk transitions. */
> #define P2M_CHANGEABLE_TYPES (p2m_to_mask(p2m_ram_rw) \
> - | p2m_to_mask(p2m_ram_logdirty) )
> + | p2m_to_mask(p2m_ram_logdirty) \
> + | p2m_to_mask(p2m_ioreq_server) )
> +
> +#define P2M_IOREQ_TYPES (p2m_to_mask(p2m_ioreq_server))
>
> #define P2M_POD_TYPES (p2m_to_mask(p2m_populate_on_demand))
>
> @@ -157,6 +160,7 @@ typedef unsigned int p2m_query_t;
> #define p2m_is_readonly(_t) (p2m_to_mask(_t) & P2M_RO_TYPES)
> #define p2m_is_discard_write(_t) (p2m_to_mask(_t) & P2M_DISCARD_WRITE_TYPES)
> #define p2m_is_changeable(_t) (p2m_to_mask(_t) & P2M_CHANGEABLE_TYPES)
> +#define p2m_is_ioreq(_t) (p2m_to_mask(_t) & P2M_IOREQ_TYPES)
I don't think this and P2M_IOREQ_TYPES are needed anymore.
> @@ -744,6 +749,25 @@ static inline p2m_type_t p2m_flags_to_type(unsigned long
> flags)
> return (flags >> 12) & 0x7f;
> }
>
> +static inline p2m_type_t p2m_recalc_type_range(bool_t recalc, p2m_type_t t,
Just "bool" please (also below).
> + struct p2m_domain *p2m,
> + unsigned long gfn_start,
> + unsigned long gfn_end)
> +{
> + if ( !recalc || !p2m_is_changeable(t) )
> + return t;
> + if ( t == p2m_ioreq_server && p2m->ioreq.server != NULL )
> + return t;
> + return p2m_is_logdirty_range(p2m, gfn_start, gfn_end) ? p2m_ram_logdirty
> + : p2m_ram_rw;
Commonly we'd align the : with either the ? or the start of the
conditional expression.
Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |