On 31-Aug-18 1:50 PM, Alejandro Lucero wrote:
Although VT-d emulation currently only supports 39 bits, it could
be iovas being within that supported range. This patch allows
IOVA mode in such a case.
Indeed, memory initialization code can be modified for using lower
virtual addresses than those used by the kernel for 64 bits processes
by default, and therefore memsegs iovas can use 39 bits or less for
most system. And this is likely 100% true for VMs.
Signed-off-by: Alejandro Lucero <alejandro.luc...@netronome.com>
---
drivers/bus/pci/linux/pci.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
index 04648ac..215dc10 100644
--- a/drivers/bus/pci/linux/pci.c
+++ b/drivers/bus/pci/linux/pci.c
@@ -588,10 +588,11 @@
fclose(fp);
mgaw = ((vtd_cap_reg & VTD_CAP_MGAW_MASK) >> VTD_CAP_MGAW_SHIFT) + 1;
- if (mgaw < X86_VA_WIDTH)
- return false;
- return true;
+ if (!rte_eal_check_dma_mask(mgaw))
+ return true;
+ else
+ return false;
return rte_eal_check_dma_mask(mgaw) == 0; ?
}
#elif defined(RTE_ARCH_PPC_64)
static bool
@@ -615,13 +616,17 @@
{
struct rte_pci_device *dev = NULL;
struct rte_pci_driver *drv = NULL;
+ int iommu_dma_mask_check_done = 0;
FOREACH_DRIVER_ON_PCIBUS(drv) {
FOREACH_DEVICE_ON_PCIBUS(dev) {
if (!rte_pci_match(drv, dev))
continue;
- if (!pci_one_device_iommu_support_va(dev))
- return false;
+ if (!iommu_dma_mask_check_done) {
+ if (!pci_one_device_iommu_support_va(dev))
+ return false;
+ iommu_dma_mask_check_done = 1;
+ }
}
The commit message doesn't explain why are we only checking a single
device. Indeed, i am not 100% clear as to why, so some explanation in
the commit message and preferably a comment in code would be more than
welcome :)
}
return true;
--
Thanks,
Anatoly
