On Tue, Jan 09, 2024 at 04:51:24PM -0500, Stewart Hildebrand wrote: > From: Oleksandr Andrushchenko <[email protected]> > > Take into account guest's BAR view and program its p2m accordingly: > gfn is guest's view of the BAR and mfn is the physical BAR value. > This way hardware domain sees physical BAR values and guest sees > emulated ones. > > Hardware domain continues getting the BARs identity mapped, while for > domUs the BARs are mapped at the requested guest address without > modifying the BAR address in the device PCI config space. > > Signed-off-by: Oleksandr Andrushchenko <[email protected]> > Signed-off-by: Volodymyr Babchuk <[email protected]> > Signed-off-by: Stewart Hildebrand <[email protected]>
Some nits and a request to add an extra assert. If you agree: Reviewed-by: Roger Pau Monné <[email protected]> > --- > In v12: > - Update guest_addr in rom_write() > - Use unsigned long for start_mfn and map_mfn to reduce mfn_x() calls > - Use existing vmsix_table_*() functions > - Change vmsix_table_base() to use .guest_addr > In v11: > - Add vmsix_guest_table_addr() and vmsix_guest_table_base() functions > to access guest's view of the VMSIx tables. > - Use MFN (not GFN) to check access permissions > - Move page offset check to this patch > - Call rangeset_remove_range() with correct parameters > In v10: > - Moved GFN variable definition outside the loop in map_range() > - Updated printk error message in map_range() > - Now BAR address is always stored in bar->guest_addr, even for > HW dom, this removes bunch of ugly is_hwdom() checks in modify_bars() > - vmsix_table_base() now uses .guest_addr instead of .addr > In v9: > - Extended the commit message > - Use bar->guest_addr in modify_bars > - Extended printk error message in map_range > - Moved map_data initialization so .bar can be initialized during declaration > Since v5: > - remove debug print in map_range callback > - remove "identity" from the debug print > Since v4: > - moved start_{gfn|mfn} calculation into map_range > - pass vpci_bar in the map_data instead of start_{gfn|mfn} > - s/guest_addr/guest_reg > Since v3: > - updated comment (Roger) > - removed gfn_add(map->start_gfn, rc); which is wrong > - use v->domain instead of v->vpci.pdev->domain > - removed odd e.g. in comment > - s/d%d/%pd in altered code > - use gdprintk for map/unmap logs > Since v2: > - improve readability for data.start_gfn and restructure ?: construct > Since v1: > - s/MSI/MSI-X in comments > --- > xen/drivers/vpci/header.c | 81 +++++++++++++++++++++++++++++++-------- > xen/include/xen/vpci.h | 3 +- > 2 files changed, 66 insertions(+), 18 deletions(-) > > diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c > index feccd070ddd0..f0b0b64b0929 100644 > --- a/xen/drivers/vpci/header.c > +++ b/xen/drivers/vpci/header.c > @@ -34,6 +34,7 @@ > > struct map_data { > struct domain *d; > + const struct vpci_bar *bar; > bool map; > }; > > @@ -41,13 +42,24 @@ static int cf_check map_range( > unsigned long s, unsigned long e, void *data, unsigned long *c) > { > const struct map_data *map = data; > + /* Start address of the BAR as seen by the guest. */ > + unsigned long start_gfn = PFN_DOWN(map->bar->guest_addr); > + /* Physical start address of the BAR. */ > + unsigned long start_mfn = PFN_DOWN(map->bar->addr); > int rc; > > for ( ; ; ) > { > unsigned long size = e - s + 1; > + /* > + * Ranges to be mapped don't always start at the BAR start address, > as > + * there can be holes or partially consumed ranges. Account for the > + * offset of the current address from the BAR start. > + */ > + unsigned long map_mfn = start_mfn + s - start_gfn; > + unsigned long m_end = map_mfn + size - 1; > > - if ( !iomem_access_permitted(map->d, s, e) ) > + if ( !iomem_access_permitted(map->d, map_mfn, m_end) ) > { > printk(XENLOG_G_WARNING > "%pd denied access to MMIO range [%#lx, %#lx]\n", > @@ -55,7 +67,8 @@ static int cf_check map_range( > return -EPERM; > } > > - rc = xsm_iomem_mapping(XSM_HOOK, map->d, s, e, map->map); > + rc = xsm_iomem_mapping(XSM_HOOK, map->d, map_mfn, m_end, > + map->map); > if ( rc ) > { > printk(XENLOG_G_WARNING > @@ -73,8 +86,8 @@ static int cf_check map_range( > * - {un}map_mmio_regions doesn't support preemption. > */ > > - rc = map->map ? map_mmio_regions(map->d, _gfn(s), size, _mfn(s)) > - : unmap_mmio_regions(map->d, _gfn(s), size, _mfn(s)); > + rc = map->map ? map_mmio_regions(map->d, _gfn(s), size, > _mfn(map_mfn)) > + : unmap_mmio_regions(map->d, _gfn(s), size, > _mfn(map_mfn)); > if ( rc == 0 ) > { > *c += size; > @@ -83,8 +96,9 @@ static int cf_check map_range( > if ( rc < 0 ) > { > printk(XENLOG_G_WARNING > - "Failed to identity %smap [%lx, %lx] for d%d: %d\n", > - map->map ? "" : "un", s, e, map->d->domain_id, rc); > + "Failed to %smap [%lx %lx] -> [%lx %lx] for %pd: %d\n", > + map->map ? "" : "un", s, e, map_mfn, > + map_mfn + size, map->d, rc); > break; > } > ASSERT(rc < size); > @@ -163,10 +177,6 @@ static void modify_decoding(const struct pci_dev *pdev, > uint16_t cmd, > bool vpci_process_pending(struct vcpu *v) > { > struct pci_dev *pdev = v->vpci.pdev; > - struct map_data data = { > - .d = v->domain, > - .map = v->vpci.cmd & PCI_COMMAND_MEMORY, > - }; > struct vpci_header *header = NULL; > unsigned int i; > > @@ -186,6 +196,11 @@ bool vpci_process_pending(struct vcpu *v) > for ( i = 0; i < ARRAY_SIZE(header->bars); i++ ) > { > struct vpci_bar *bar = &header->bars[i]; > + struct map_data data = { > + .d = v->domain, > + .map = v->vpci.cmd & PCI_COMMAND_MEMORY, > + .bar = bar, > + }; > int rc; > > if ( rangeset_is_empty(bar->mem) ) > @@ -236,7 +251,6 @@ bool vpci_process_pending(struct vcpu *v) > static int __init apply_map(struct domain *d, const struct pci_dev *pdev, > uint16_t cmd) > { > - struct map_data data = { .d = d, .map = true }; > struct vpci_header *header = &pdev->vpci->header; > int rc = 0; > unsigned int i; > @@ -246,6 +260,7 @@ static int __init apply_map(struct domain *d, const > struct pci_dev *pdev, > for ( i = 0; i < ARRAY_SIZE(header->bars); i++ ) > { > struct vpci_bar *bar = &header->bars[i]; > + struct map_data data = { .d = d, .map = true, .bar = bar }; > > if ( rangeset_is_empty(bar->mem) ) > continue; > @@ -311,12 +326,16 @@ static int modify_bars(const struct pci_dev *pdev, > uint16_t cmd, bool rom_only) > * First fill the rangesets with the BAR of this device or with the ROM > * BAR only, depending on whether the guest is toggling the memory decode > * bit of the command register, or the enable bit of the ROM BAR > register. > + * > + * For non-hardware domain we use guest physical addresses. > */ > for ( i = 0; i < ARRAY_SIZE(header->bars); i++ ) > { > struct vpci_bar *bar = &header->bars[i]; > unsigned long start = PFN_DOWN(bar->addr); > unsigned long end = PFN_DOWN(bar->addr + bar->size - 1); > + unsigned long start_guest = PFN_DOWN(bar->guest_addr); > + unsigned long end_guest = PFN_DOWN(bar->guest_addr + bar->size - 1); > > if ( !bar->mem ) > continue; > @@ -336,11 +355,25 @@ static int modify_bars(const struct pci_dev *pdev, > uint16_t cmd, bool rom_only) > continue; > } Should we assert that the BAR rangeset is empty here? To stay on the safe side. > > - rc = rangeset_add_range(bar->mem, start, end); > + /* > + * Make sure that the guest set address has the same page offset > + * as the physical address on the host or otherwise things won't > work as > + * expected. > + */ > + if ( PAGE_OFFSET(bar->guest_addr) != PAGE_OFFSET(bar->addr) ) > + { > + gprintk(XENLOG_G_WARNING, > + "%pp: Can't map BAR%d because of page offset mismatch: > %lx vs %lx\n", ^u Also when using the x modifier it's better to also use # to print the 0x prefix. You can also reduce the length of the message using s/because of/due to/ IMO: %pp: Can't map BAR%u due to offset mismatch: %lx vs %lx > + &pdev->sbdf, i, PAGE_OFFSET(bar->guest_addr), > + PAGE_OFFSET(bar->addr)); Maybe worth printing the whole address? > + return -EINVAL; > + } > + > + rc = rangeset_add_range(bar->mem, start_guest, end_guest); > if ( rc ) > { > printk(XENLOG_G_WARNING "Failed to add [%lx, %lx]: %d\n", > - start, end, rc); > + start_guest, end_guest, rc); > return rc; > } > > @@ -352,12 +385,12 @@ static int modify_bars(const struct pci_dev *pdev, > uint16_t cmd, bool rom_only) > if ( rangeset_is_empty(prev_bar->mem) ) > continue; > > - rc = rangeset_remove_range(prev_bar->mem, start, end); > + rc = rangeset_remove_range(prev_bar->mem, start_guest, > end_guest); > if ( rc ) > { > gprintk(XENLOG_WARNING, > "%pp: failed to remove overlapping range [%lx, %lx]: > %d\n", > - &pdev->sbdf, start, end, rc); > + &pdev->sbdf, start_guest, end_guest, rc); > return rc; > } > } > @@ -425,8 +458,8 @@ static int modify_bars(const struct pci_dev *pdev, > uint16_t cmd, bool rom_only) > for ( i = 0; i < ARRAY_SIZE(tmp->vpci->header.bars); i++ ) > { > const struct vpci_bar *remote_bar = > &tmp->vpci->header.bars[i]; > - unsigned long start = PFN_DOWN(remote_bar->addr); > - unsigned long end = PFN_DOWN(remote_bar->addr + > + unsigned long start = PFN_DOWN(remote_bar->guest_addr); > + unsigned long end = PFN_DOWN(remote_bar->guest_addr + > remote_bar->size - 1); > > if ( !remote_bar->enabled ) > @@ -513,6 +546,8 @@ static void cf_check bar_write( > struct vpci_bar *bar = data; > bool hi = false; > > + ASSERT(is_hardware_domain(pdev->domain)); > + > if ( bar->type == VPCI_BAR_MEM64_HI ) > { > ASSERT(reg > PCI_BASE_ADDRESS_0); > @@ -543,6 +578,10 @@ static void cf_check bar_write( > */ > bar->addr &= ~(0xffffffffULL << (hi ? 32 : 0)); > bar->addr |= (uint64_t)val << (hi ? 32 : 0); > + /* > + * Update guest address as well, so hardware domain sees BAR identity > mapped > + */ Can you drop the 'as well' and make this a single line comment? Otherwise maybe reword to: Update guest address, so hardware domain BAR is identity mapped. Sorry, I find it wasteful to have the opening and closing comment delimiters in separate lines for single line comments. Thanks, Roger.
