On Wed, Nov 11, 2026 at 09:09:27PM +0200, Leon Romanovsky wrote: > The only sane approach is to do the cleanup first and then build the p2p > changes on top of it.
Done in v5 [1]. It adds an empty <asm-generic/cpu_device_id.h>, so <asm/cpu_device_id.h> can be included without #ifdef CONFIG_X86, and the P2PDMA patch sits on top of it. The <asm/intel-family.h> include is dropped, as <asm/cpu_device_id.h> already pulls it in on x86. The follow-up series [2] removes the same #ifdef around the include in the other users (ACPI, cpufreq, i915, amdgpu, tpm, ccp, platform/x86). > If you are ready, why hasn't it been done until now? I missed your "general asm stubs" hint and read "properly exposed" as moving the x86 headers under include/linux/, with the aim of dropping CONFIG_X86 from the P2PDMA code entirely. As that is a much larger change, I proposed doing it later. [1] https://lore.kernel.org/r/[email protected] [2] https://lore.kernel.org/r/[email protected] Thanks, Pavel > -----Original Message----- > From: Leon Romanovsky <[email protected]> > Sent: Wednesday, November 11, 2026 12:10 PM > To: Popov, Pavel E <[email protected]> > Cc: Bjorn Helgaas <[email protected]>; Logan Gunthorpe > <[email protected]>; Lukas Wunner <[email protected]>; Jim Chow > <[email protected]>; Radu Rugina <[email protected]>; > Alexey Makhalov <[email protected]>; Wei Liu > <[email protected]>; Michael Kelley <[email protected]>; Nathan > Ciobanu <[email protected]>; bcm-kernel-feedback- > [email protected]; [email protected]; linux- > [email protected]; [email protected]; linux- > [email protected] > Subject: Re: [PATCH v4 0/2] PCI/P2PDMA: Allow P2PDMA on Intel Xeon > server CPUs > > On Wed, Nov 11, 2026 at 03:37:13PM +0000, Popov, Pavel E wrote: > > On Wed, Nov 11, 2026 at 10:10:57AM +0200, Leon Romanovsky wrote: > > > Peer-to-peer is a general concept, and the code should reflect that. > > > It is reasonable to expect you to join the effort and help clean it up. > > > > I'm in. My proposal is to do it after this series, since this one > > unblocks P2PDMA in guests and the cleanup is out of PCI scope: even > > the minimal fix for p2pdma.c alone means changes under arch/x86, so it > > would no longer be a P2PDMA patch but an x86 header series with its > > own maintainers and review. That x86 header series is also the right > > place to drop the same guard from six other files, and I'm ready to do > > it: > > If you are ready, why hasn't it been done until now? > > The claims of urgency are hard to take seriously: `SKYLAKE_X` was added to > `arch/x86/include/asm/intel-family.h` in 2016, and now, ten years later, you > are asking us to "do it urgently." I strongly suspect that if I don't bring > up P2P > at LPC, we won't see this patch for another ten years. > > Even now, despite being asked to clean this up before the merge window, you > still haven't done so. Trust is built by following through, not by making > promises. > > > > > drivers/acpi/mipi-disco-img.c > > drivers/cpufreq/cpufreq_ondemand.h > > drivers/gpu/drm/i915/intel_cpu_info.c > > drivers/char/tpm/tpm.h > > drivers/crypto/ccp/ccp-dev.c > > include/linux/platform_data/x86/soc.h > > > > Bjorn, is v4 OK for v7.5 as is? The x86 header series will follow on > > top. > > I disagree. You can't build this on top, as it would need to go through > different > trees and would likely cause merge conflicts. The cleanup series would have to > touch the same lines in the PCI subsystem that you are changing now. > > The only sane approach is to do the cleanup first and then build the p2p > changes on top of it. > > Thanks > > > > > Thanks, > > Pavel > > > > > -----Original Message----- > > > From: Leon Romanovsky <[email protected]> > > > Sent: Wednesday, November 11, 2026 1:11 AM > > > To: Popov, Pavel E <[email protected]> > > > Cc: Bjorn Helgaas <[email protected]>; Logan Gunthorpe > > > <[email protected]>; Lukas Wunner <[email protected]>; Jim Chow > > > <[email protected]>; Radu Rugina > <[email protected]>; > > > Alexey Makhalov <[email protected]>; Wei Liu > > > <[email protected]>; Michael Kelley <[email protected]>; Nathan > > > Ciobanu <[email protected]>; bcm-kernel-feedback- > > > [email protected]; [email protected]; linux- > > > [email protected]; [email protected]; linux- > > > [email protected] > > > Subject: Re: [PATCH v4 0/2] PCI/P2PDMA: Allow P2PDMA on Intel Xeon > > > server CPUs > > > > > > On Wed, Nov 11, 2026 at 03:48:07AM +0000, Popov, Pavel E wrote: > > > > Hi Bjorn, > > > > > > > > Gentle ping on this series. Is this OK for v7.5? > > > > > > I would say no. An Intel employee was asked to clean up an > > > Intel-created mess while upstreaming an Intel-specific patch. > > > > > > Peer-to-peer is a general concept, and the code should reflect that. > > > It is reasonable to expect you to join the effort and help clean it up. > > > > > > Thanks > > > > > > > > > > > Thanks, > > > > Pavel > > > > > > > > > -----Original Message----- > > > > > From: Popov, Pavel E <[email protected]> > > > > > Sent: Tuesday, October 20, 2026 10:38 AM > > > > > To: Bjorn Helgaas <[email protected]>; Logan Gunthorpe > > > > > <[email protected]> > > > > > Cc: Popov, Pavel E <[email protected]>; Leon Romanovsky > > > > > <[email protected]>; Lukas Wunner <[email protected]>; Jim Chow > > > > > <[email protected]>; Radu Rugina > > > <[email protected]>; > > > > > Alexey Makhalov <[email protected]>; Wei Liu > > > > > <[email protected]>; Michael Kelley <[email protected]>; > > > > > Nathan Ciobanu <[email protected]>; > > > > > bcm-kernel-feedback- [email protected]; > > > > > [email protected]; linux- [email protected]; > > > > > [email protected]; linux- [email protected] > > > > > Subject: [PATCH v4 0/2] PCI/P2PDMA: Allow P2PDMA on Intel Xeon > > > > > server CPUs > > > > > > > > > > VMware and Hyper-V expose passthrough devices to guest VMs > > > > > without an explicit host bridge device. Consequently, > > > > > host_bridge_whitelist() cannot automatically identify the > > > > > underlying host bridge structure, causing Peer-to- Peer DMA > > > > > (P2PDMA) requests to be rejected unless the device IDs are > > > > > explicitly listed in pci_p2pdma_whitelist[]. To enable P2PDMA on > > > > > Intel hosts, this series extends cpu_supports_p2pdma(), which so > > > > > far covers AMD Zen and > > > newer, with an explicit list of Intel Xeon server generations. > > > > > > > > > > Patch 1 moves the CONFIG_X86 #ifdef out of cpu_supports_p2pdma(). > > > > > Patch 2 is the v3 patch rebased on it, with Logan's Reviewed-by > > > > > carried over; the Xeon list and the check are unchanged. > > > > > > > > > > Changes in v4: > > > > > - Add 1/2, moving the CONFIG_X86 #ifdef out of > cpu_supports_p2pdma() > > > > > (Logan Gunthorpe, Leon Romanovsky) > > > > > - Keep the #ifdef around the asm/ includes, as these headers exist > > > > > only on x86 (Bjorn Helgaas) > > > > > > > > > > Changes in v3: > > > > > - Drop the hypervisor check and move the Xeon list into > > > > > cpu_supports_p2pdma(), next to the AMD check, as suggested by > Logan > > > > > Gunthorpe and Leon Romanovsky [1] > > > > > - Fold the VMware and Hyper-V patches into one, as the check no > longer > > > > > depends on the hypervisor > > > > > > > > > > Changes in v2: > > > > > - Replace the Skylake-and-newer threshold with an explicit list of > > > > > Intel > > > > > Xeon server generations, from Skylake-SP to Diamond Rapids (Logan > > > > > Gunthorpe) > > > > > - Move the CONFIG_X86 #ifdef out of hypervisor_supports_p2pdma() > > > > > (Logan Gunthorpe) > > > > > - Rebased on current mainline > > > > > > > > > > [1] https://lore.kernel.org/r/20261016153147.GC219304@unreal > > > > > > > > > > v3: https://lore.kernel.org/r/20261020151305.65218-1- > > > > > [email protected] > > > > > v2: https://lore.kernel.org/r/20261016223402.19991-1- > > > > > [email protected] > > > > > v1: https://lore.kernel.org/r/20261009154034.82321-1- > > > > > [email protected] > > > > > > > > > > Pavel Popov (2): > > > > > PCI/P2PDMA: Move CONFIG_X86 #ifdef out of > cpu_supports_p2pdma() > > > > > PCI/P2PDMA: Allow P2PDMA on Intel Xeon server CPUs > > > > > > > > > > drivers/pci/p2pdma.c | 33 +++++++++++++++++++++++++++++++-- > > > > > 1 file changed, 31 insertions(+), 2 deletions(-) > > > > > > > > > > > > > > > base-commit: c03c1a14507dfaf8b856c2608f9ac216021fc222 > > > > > -- > > > > > 2.53.0 > > > > > >
