On Fri, Aug 16, 2019 at 4:42 AM M. Vefa Bicakci <m.v.b@xxxxxxxxxx> wrote: > > On a Xen-based PVH virtual machine with more than 4 GiB of RAM, > intel_pmc_core fails initialization with the following warning message > from the kernel, indicating that the driver is attempting to ioremap > RAM: > > ------------[ cut here ]------------ > ioremap on RAM at 0x00000000fe000000 - 0x00000000fe001fff > This issue appears to manifest itself because of the following fallback > mechanism in the driver: > > if (lpit_read_residency_count_address(&slp_s0_addr)) > pmcdev->base_addr = PMC_BASE_ADDR_DEFAULT; > > The validity of address PMC_BASE_ADDR_DEFAULT (i.e., 0xFE000000) is not > verified by the driver, which is what this patch introduces. With this > patch, if address PMC_BASE_ADDR_DEFAULT is in RAM, then the driver will > not attempt to ioremap the aforementioned address. Thank you for the patch. Is there anything preventing us to use memremap() in such case? -- With Best Regards, Andy Shevchenko