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IOMMU/x86: switch to alternatives-call patching in further instances
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This is, once again, to limit the number of indirect calls as much as
possible. The only hook invocation which isn't sensible to convert is
setup(). And of course Arm-only use sites are left alone as well.

Note regarding the introduction / use of local variables in pci.c:
struct pci_dev's involved fields are const. This const propagates, via
typeof(), to the local helper variables in the altcall macros. These
helper variables are, however, used as outputs (and hence can't be
const). In iommu_get_device_group() make use of the new local variables
to also simplify some adjacent code.

Signed-off-by: Jan Beulich <[email protected]>
Reviewed-by: Paul Durrant <[email protected]>
Reviewed-by: Rahul Singh <[email protected]>
Tested-by: Rahul Singh <[email protected]>
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@jbeulich
jbeulich committed Jan 31, 2022
1 parent c5539e6 commit f66e3d6
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Showing 3 changed files with 32 additions and 27 deletions.
8 changes: 4 additions & 4 deletions xen/drivers/passthrough/iommu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -198,7 +198,7 @@ int iommu_domain_init(struct domain *d, unsigned int opts)
return ret;

hd->platform_ops = iommu_get_ops();
ret = hd->platform_ops->init(d);
ret = iommu_call(hd->platform_ops, init, d);
if ( ret || is_system_domain(d) )
return ret;

Expand Down Expand Up @@ -233,7 +233,7 @@ void __hwdom_init iommu_hwdom_init(struct domain *d)

register_keyhandler('o', &iommu_dump_page_tables, "dump iommu page tables", 0);

hd->platform_ops->hwdom_init(d);
iommu_vcall(hd->platform_ops, hwdom_init, d);
}

static void iommu_teardown(struct domain *d)
Expand Down Expand Up @@ -576,7 +576,7 @@ int iommu_get_reserved_device_memory(iommu_grdm_t *func, void *ctxt)
if ( !ops->get_reserved_device_memory )
return 0;

return ops->get_reserved_device_memory(func, ctxt);
return iommu_call(ops, get_reserved_device_memory, func, ctxt);
}

bool_t iommu_has_feature(struct domain *d, enum iommu_feature feature)
Expand All @@ -603,7 +603,7 @@ static void iommu_dump_page_tables(unsigned char key)
continue;
}

dom_iommu(d)->platform_ops->dump_page_tables(d);
iommu_vcall(dom_iommu(d)->platform_ops, dump_page_tables, d);
}

rcu_read_unlock(&domlist_read_lock);
Expand Down
47 changes: 26 additions & 21 deletions xen/drivers/passthrough/pci.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -861,15 +861,15 @@ static int deassign_device(struct domain *d, uint16_t seg, uint8_t bus,
devfn += pdev->phantom_stride;
if ( PCI_SLOT(devfn) != PCI_SLOT(pdev->devfn) )
break;
ret = hd->platform_ops->reassign_device(d, target, devfn,
pci_to_dev(pdev));
ret = iommu_call(hd->platform_ops, reassign_device, d, target, devfn,
pci_to_dev(pdev));
if ( ret )
goto out;
}

devfn = pdev->devfn;
ret = hd->platform_ops->reassign_device(d, target, devfn,
pci_to_dev(pdev));
ret = iommu_call(hd->platform_ops, reassign_device, d, target, devfn,
pci_to_dev(pdev));
if ( ret )
goto out;

Expand Down Expand Up @@ -1300,7 +1300,7 @@ static int iommu_add_device(struct pci_dev *pdev)
{
const struct domain_iommu *hd;
int rc;
u8 devfn;
unsigned int devfn = pdev->devfn;

if ( !pdev->domain )
return -EINVAL;
Expand All @@ -1311,16 +1311,16 @@ static int iommu_add_device(struct pci_dev *pdev)
if ( !is_iommu_enabled(pdev->domain) )
return 0;

rc = hd->platform_ops->add_device(pdev->devfn, pci_to_dev(pdev));
rc = iommu_call(hd->platform_ops, add_device, devfn, pci_to_dev(pdev));
if ( rc || !pdev->phantom_stride )
return rc;

for ( devfn = pdev->devfn ; ; )
for ( ; ; )
{
devfn += pdev->phantom_stride;
if ( PCI_SLOT(devfn) != PCI_SLOT(pdev->devfn) )
return 0;
rc = hd->platform_ops->add_device(devfn, pci_to_dev(pdev));
rc = iommu_call(hd->platform_ops, add_device, devfn, pci_to_dev(pdev));
if ( rc )
printk(XENLOG_WARNING "IOMMU: add %pp failed (%d)\n",
&pdev->sbdf, rc);
Expand All @@ -1341,7 +1341,7 @@ static int iommu_enable_device(struct pci_dev *pdev)
!hd->platform_ops->enable_device )
return 0;

return hd->platform_ops->enable_device(pci_to_dev(pdev));
return iommu_call(hd->platform_ops, enable_device, pci_to_dev(pdev));
}

static int iommu_remove_device(struct pci_dev *pdev)
Expand All @@ -1363,15 +1363,18 @@ static int iommu_remove_device(struct pci_dev *pdev)
devfn += pdev->phantom_stride;
if ( PCI_SLOT(devfn) != PCI_SLOT(pdev->devfn) )
break;
rc = hd->platform_ops->remove_device(devfn, pci_to_dev(pdev));
rc = iommu_call(hd->platform_ops, remove_device, devfn,
pci_to_dev(pdev));
if ( !rc )
continue;

printk(XENLOG_ERR "IOMMU: remove %pp failed (%d)\n", &pdev->sbdf, rc);
return rc;
}

return hd->platform_ops->remove_device(pdev->devfn, pci_to_dev(pdev));
devfn = pdev->devfn;

return iommu_call(hd->platform_ops, remove_device, devfn, pci_to_dev(pdev));
}

static int device_assigned(u16 seg, u8 bus, u8 devfn)
Expand Down Expand Up @@ -1421,15 +1424,17 @@ static int assign_device(struct domain *d, u16 seg, u8 bus, u8 devfn, u32 flag)

pdev->fault.count = 0;

if ( (rc = hd->platform_ops->assign_device(d, devfn, pci_to_dev(pdev), flag)) )
if ( (rc = iommu_call(hd->platform_ops, assign_device, d, devfn,
pci_to_dev(pdev), flag)) )
goto done;

for ( ; pdev->phantom_stride; rc = 0 )
{
devfn += pdev->phantom_stride;
if ( PCI_SLOT(devfn) != PCI_SLOT(pdev->devfn) )
break;
rc = hd->platform_ops->assign_device(d, devfn, pci_to_dev(pdev), flag);
rc = iommu_call(hd->platform_ops, assign_device, d, devfn,
pci_to_dev(pdev), flag);
}

done:
Expand Down Expand Up @@ -1457,24 +1462,24 @@ static int iommu_get_device_group(
if ( !is_iommu_enabled(d) || !ops->get_device_group_id )
return 0;

group_id = ops->get_device_group_id(seg, bus, devfn);
group_id = iommu_call(ops, get_device_group_id, seg, bus, devfn);

pcidevs_lock();
for_each_pdev( d, pdev )
{
if ( (pdev->seg != seg) ||
((pdev->bus == bus) && (pdev->devfn == devfn)) )
unsigned int b = pdev->bus;
unsigned int df = pdev->devfn;

if ( (pdev->seg != seg) || ((b == bus) && (df == devfn)) )
continue;

if ( xsm_get_device_group(XSM_HOOK, (seg << 16) | (pdev->bus << 8) | pdev->devfn) )
if ( xsm_get_device_group(XSM_HOOK, (seg << 16) | (b << 8) | df) )
continue;

sdev_id = ops->get_device_group_id(seg, pdev->bus, pdev->devfn);
sdev_id = iommu_call(ops, get_device_group_id, seg, b, df);
if ( (sdev_id == group_id) && (i < max_sdevs) )
{
bdf = 0;
bdf |= (pdev->bus & 0xff) << 16;
bdf |= (pdev->devfn & 0xff) << 8;
bdf = (b << 16) | (df << 8);

if ( unlikely(copy_to_guest_offset(buf, i, &bdf, 1)) )
{
Expand Down
4 changes: 2 additions & 2 deletions xen/drivers/passthrough/x86/iommu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -145,7 +145,7 @@ unsigned int iommu_read_apic_from_ire(unsigned int apic, unsigned int reg)
int __init iommu_setup_hpet_msi(struct msi_desc *msi)
{
const struct iommu_ops *ops = iommu_get_ops();
return ops->setup_hpet_msi ? ops->setup_hpet_msi(msi) : -ENODEV;
return ops->setup_hpet_msi ? iommu_call(ops, setup_hpet_msi, msi) : -ENODEV;
}

void __hwdom_init arch_iommu_check_autotranslated_hwdom(struct domain *d)
Expand Down Expand Up @@ -406,7 +406,7 @@ int iommu_free_pgtables(struct domain *d)
* Pages will be moved to the free list below. So we want to
* clear the root page-table to avoid any potential use after-free.
*/
hd->platform_ops->clear_root_pgtable(d);
iommu_vcall(hd->platform_ops, clear_root_pgtable, d);

while ( (pg = page_list_remove_head(&hd->arch.pgtables.list)) )
{
Expand Down

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