On Mon, Jan 19, 2026 at 07:59:37AM -0800, [email protected] wrote: > From: Michael Kelley <[email protected]> > > When running with a paravisor and SEV-SNP, the GHCB page is provided > by the paravisor instead of being allocated by Linux. The provided page > is normal memory, but is outside of the physical address space seen by > Linux. As such it cannot be accessed via the kernel's direct map, and > must be explicitly mapped to a kernel virtual address. > > Current code uses ioremap_cache() and iounmap() to map and unmap the page. > These functions are for use on I/O address space that may not behave as > normal memory, so they generate or expect addresses with the __iomem > attribute. For normal memory, the preferred functions are memremap() and > memunmap(), which operate similarly but without __iomem. > > At the time of the original work on CoCo VMs on Hyper-V, memremap() did not > support creating a decrypted mapping, so ioremap_cache() was used instead, > since I/O address space is always mapped decrypted. memremap() has since > been enhanced to allow decrypted mappings, so replace ioremap_cache() with > memremap() when mapping the GHCB page. Similarly, replace iounmap() with > memunmap(). As a side benefit, the replacement cleans up 'sparse' warnings > about __iomem mismatches. > > The replacement is done to use the correct functions as long-term goodness > and to clean up the sparse warnings. No runtime bugs are fixed. > > Reported-by: kernel test robot <[email protected]> > Closes: > https://lore.kernel.org/oe-kbuild-all/[email protected]/ > Signed-off-by: Michael Kelley <[email protected]>
Applied to hyperv-next. Thanks.
