śr., 20 lip 2022 o 17:22 Limonciello, Mario <mario.limonciello@xxxxxxx> napisał(a): > > >> It looks like you want suspend-to-idle to behave like S3 and it won't. > > > > In a way, yes, we compensate for the lack of something like PM1_CNT to > > trap on for detecting that the guest is suspending. > > We could instead force the guest to use S3 but IMO it is undesirable, > > since it generally does make a difference which suspend mode is used > > in the guest, s2idle or S3, e.g some drivers check which suspend type > > is used and based on that behaves differently during suspend. One of > > the example is: > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Fv5.18.12%2Fsource%2Fdrivers%2Fgpu%2Fdrm%2Famd%2Famdgpu%2Famdgpu_drv.c%23L2323&data=05%7C01%7Cmario.limonciello%40amd.com%7C7bdd972291324d03847e08da6a51ff4f%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637939197694682503%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=5M1sn3iRybQzSFi3ojQ4YTJuW41DlgJNl5sxbWEvLBQ%3D&reserved=0 > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Fv5.18.12%2Fsource%2Fdrivers%2Fgpu%2Fdrm%2Famd%2Famdgpu%2Famdgpu_acpi.c%23L1069&data=05%7C01%7Cmario.limonciello%40amd.com%7C7bdd972291324d03847e08da6a51ff4f%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637939197694682503%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=fIrLmZAgpIRPYO4to4uYUoBSEWXmz1lr%2BTnR14kAfvM%3D&reserved=0 > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Fv5.18.12%2Fsource%2Fdrivers%2Fgpu%2Fdrm%2Famd%2Famdgpu%2Famdgpu_gfx.c%23L583&data=05%7C01%7Cmario.limonciello%40amd.com%7C7bdd972291324d03847e08da6a51ff4f%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637939197694682503%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=SNsbmpV4HrgA%2Bkff4JzRodNDzKvwM5tnkGDvrKO44dc%3D&reserved=0 > > > > Actually I recently was suggesting a change to add this detection to > another driver to set a policy and Rafael pushed back. He's actively > removing it from other places in the kernel. > > For amdgpu stuff you pointed above, are you wanting to pass through the > PCIe GPU device to a guest and then suspend that guest? Or is this just > illustrative? Just illustrative. I am not focused on amdgpu stuff right now. Thank you, Grzegorz > > For a dGPU I would expect it works, but I don't think passing an APU's > GPU PCIe endpoint would functionally work (there were bugs reported on > this I recall). > > That code path you point out only has special handling for APU when > headed to S0ix and that's because the GPU driver happens to be where the > control point is for some common silicon functions. If the bug I > mentioned about PCIe passthrough of the APU GPU endpoint to the guest is > fixed and the guest needs to do s0ix when the host doesn't we're going > to have other breakage to worry about because of that common silicon > functionality I mentioned.
