[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] x86/iommu: introduce a rangeset to perform hwdom IOMMU setup
commit c27c8922f2c6995d688437b0758cec6a27d18320 Author: Roger Pau Monné <roger.pau@xxxxxxxxxx> AuthorDate: Tue Jan 9 14:07:49 2024 +0100 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Tue Jan 9 14:07:49 2024 +0100 x86/iommu: introduce a rangeset to perform hwdom IOMMU setup This change just introduces the boilerplate code in order to use a rangeset when setting up the hardware domain IOMMU mappings. The rangeset is never populated in this patch, so it's a non-functional change as far as the mappings the domain gets established. Note there will be a change for HVM domains (ie: PVH dom0) when the code introduced here gets used: the p2m mappings will be established using map_mmio_regions() instead of p2m_add_identity_entry(), so that ranges can be mapped with a single function call if possible. Note that the interface of map_mmio_regions() doesn't allow creating read-only mappings, but so far there are no such mappings created for PVH dom0 in arch_iommu_hwdom_init(). Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> --- xen/drivers/passthrough/x86/iommu.c | 103 ++++++++++++++++++++++++++++++++++-- 1 file changed, 100 insertions(+), 3 deletions(-) diff --git a/xen/drivers/passthrough/x86/iommu.c b/xen/drivers/passthrough/x86/iommu.c index 857dccb6a4..59b0c7e980 100644 --- a/xen/drivers/passthrough/x86/iommu.c +++ b/xen/drivers/passthrough/x86/iommu.c @@ -370,10 +370,88 @@ static unsigned int __hwdom_init hwdom_iommu_map(const struct domain *d, return perms; } +struct map_data { + struct domain *d; + unsigned int flush_flags; + bool mmio_ro; +}; + +static int __hwdom_init cf_check identity_map(unsigned long s, unsigned long e, + void *data) +{ + struct map_data *info = data; + struct domain *d = info->d; + long rc; + + if ( iommu_verbose ) + printk(XENLOG_INFO " [%010lx, %010lx] R%c\n", + s, e, info->mmio_ro ? 'O' : 'W'); + + if ( paging_mode_translate(d) ) + { + if ( info->mmio_ro ) + { + ASSERT_UNREACHABLE(); + /* End the rangeset iteration, as other regions will also fail. */ + return -EOPNOTSUPP; + } + while ( (rc = map_mmio_regions(d, _gfn(s), e - s + 1, _mfn(s))) > 0 ) + { + s += rc; + process_pending_softirqs(); + } + } + else + { + const unsigned int perms = IOMMUF_readable | IOMMUF_preempt | + (info->mmio_ro ? 0 : IOMMUF_writable); + + /* + * Read-only ranges are strictly MMIO and need an additional iomem + * permissions check. + */ + while ( info->mmio_ro && s <= e && !iomem_access_permitted(d, s, e) ) + { + /* + * Consume a frame per iteration until the remainder is accessible + * or there's nothing left to map. + */ + if ( iomem_access_permitted(d, s, s) ) + { + rc = iommu_map(d, _dfn(s), _mfn(s), 1, perms, + &info->flush_flags); + if ( rc < 0 ) + break; + /* Must map a frame at least, which is what we request for. */ + ASSERT(rc == 1); + process_pending_softirqs(); + } + s++; + } + while ( (rc = iommu_map(d, _dfn(s), _mfn(s), e - s + 1, + perms, &info->flush_flags)) > 0 ) + { + s += rc; + process_pending_softirqs(); + } + } + ASSERT(rc <= 0); + if ( rc ) + printk(XENLOG_WARNING + "IOMMU identity mapping of [%lx, %lx] failed: %ld\n", + s, e, rc); + + /* Ignore errors and attempt to map the remaining regions. */ + return 0; +} + void __hwdom_init arch_iommu_hwdom_init(struct domain *d) { unsigned long i, top, max_pfn, start, count; - unsigned int flush_flags = 0, start_perms = 0; + unsigned int start_perms = 0; + struct rangeset *map; + struct map_data map_data = { .d = d }; + int rc; BUG_ON(!is_hardware_domain(d)); @@ -397,6 +475,10 @@ void __hwdom_init arch_iommu_hwdom_init(struct domain *d) if ( iommu_hwdom_passthrough ) return; + map = rangeset_new(NULL, NULL, 0); + if ( !map ) + panic("IOMMU init: unable to allocate rangeset\n"); + max_pfn = (GB(4) >> PAGE_SHIFT) - 1; top = max(max_pdx, pfn_to_pdx(max_pfn) + 1); @@ -427,7 +509,7 @@ void __hwdom_init arch_iommu_hwdom_init(struct domain *d) commit: while ( (rc = iommu_map(d, _dfn(start), _mfn(start), count, start_perms | IOMMUF_preempt, - &flush_flags)) > 0 ) + &map_data.flush_flags)) > 0 ) { start += rc; count -= rc; @@ -451,8 +533,23 @@ void __hwdom_init arch_iommu_hwdom_init(struct domain *d) goto commit; } + if ( iommu_verbose ) + printk(XENLOG_INFO "%pd: identity mappings for IOMMU:\n", d); + + rc = rangeset_report_ranges(map, 0, ~0UL, identity_map, &map_data); + rangeset_destroy(map); + if ( !rc && is_pv_domain(d) ) + { + map_data.mmio_ro = true; + rc = rangeset_report_ranges(mmio_ro_ranges, 0, ~0UL, identity_map, + &map_data); + } + if ( rc ) + printk(XENLOG_WARNING "IOMMU unable to create %smappings: %d\n", + map_data.mmio_ro ? "read-only " : "", rc); + /* Use if to avoid compiler warning */ - if ( iommu_iotlb_flush_all(d, flush_flags) ) + if ( iommu_iotlb_flush_all(d, map_data.flush_flags) ) return; } -- generated by git-patchbot for /home/xen/git/xen.git#master
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