> -----Original Message----- > From: Burakov, Anatoly <anatoly.bura...@intel.com> > Sent: Tuesday, July 9, 2019 3:15 PM > To: Jerin Jacob Kollanukkaran <jer...@marvell.com>; David Marchand > <david.march...@redhat.com> > Cc: dev <dev@dpdk.org>; Thomas Monjalon <tho...@monjalon.net>; Ben > Walker <benjamin.wal...@intel.com> > Subject: Re: [EXT] Re: [dpdk-dev] [PATCH] bus/pci: fix IOVA as VA mode > selection > > On 08-Jul-19 8:13 PM, Jerin Jacob Kollanukkaran wrote: > > See below, > > > > Please send the email as text to avoid formatting issue.(No HTML) > > > > From: David Marchand <david.march...@redhat.com> > > Sent: Tuesday, July 9, 2019 12:09 AM > > To: Jerin Jacob Kollanukkaran <jer...@marvell.com> > > Cc: dev <dev@dpdk.org>; Thomas Monjalon <tho...@monjalon.net>; > Ben > > Walker <benjamin.wal...@intel.com>; Burakov, Anatoly > > <anatoly.bura...@intel.com> > > Subject: [EXT] Re: [dpdk-dev] [PATCH] bus/pci: fix IOVA as VA mode > > selection > > > > ________________________________________ > > > > On Mon, Jul 8, 2019 at 4:25 PM <mailto:jer...@marvell.com> wrote: > > From: Jerin Jacob <mailto:jer...@marvell.com> > > > > Existing logic fails to select IOVA mode as VA if driver request to > > enable IOVA as VA. > > > > IOVA as VA has more strict requirement than other modes, so enabling > > positive logic for IOVA as VA selection. > > > > This patch also updates the default IOVA mode as PA for PCI devices as > > it has to deal with DMA engines unlike the virtual devices that may > > need only IOVA as DC. > > > > We have three cases: > > - driver/hw supports IOVA as PA only > > > > [Jerin] It is not driver cap, it is more of system cap(IOMMU vs non > > IOMMU). We are already addressing that case > > I don't get how this works. How does "system capability" affect what the > device itself supports? Are we to assume that *all* hardware support IOVA > as VA by default? "System capability" is more of a bus issue than an > individual > device issue, is it not?
What I meant is, supporting VA vs PA is function of IOMMU(not the device attribute). Ie. Device makes the bus master request, if IOMMU available and enabled in the SYSTEM , It goes over IOMMU and translate the IOVA to physical address. Another way to put is, Is there any _PCIe_ device which need/requires RTE_PCI_DRV_NEED_IOVA_AS_PA in rte_pci_driver.drv_flags > > -- > Thanks, > Anatoly
