54d8c1d326
[ Upstream commit 7e8037b099c0bbe8f2109dc452dbcab8d400fc53 ] A Gen2 VM doesn't support legacy PCI/PCIe, so both raw_pci_ops and raw_pci_ext_ops are NULL, and pci_subsys_init() -> pcibios_init() doesn't call pcibios_resource_survey() -> e820__reserve_resources_late(); as a result, any emulated persistent memory of E820_TYPE_PRAM (12) via the kernel parameter memmap=nn[KMG]!ss is not added into iomem_resource and hence can't be detected by register_e820_pmem(). Fix this by directly calling e820__reserve_resources_late() in hv_pci_init(), which is called from arch_initcall(pci_arch_init). It's ok to move a Gen2 VM's e820__reserve_resources_late() from subsys_initcall(pci_subsys_init) to arch_initcall(pci_arch_init) because the code in-between doesn't depend on the E820 resources. e820__reserve_resources_late() depends on e820__reserve_resources(), which has been called earlier from setup_arch(). For a Gen-2 VM, the new hv_pci_init() also adds any memory of E820_TYPE_PMEM (7) into iomem_resource, and acpi_nfit_register_region() -> acpi_nfit_insert_resource() -> region_intersects() returns REGION_INTERSECTS, so the memory of E820_TYPE_PMEM won't get added twice. Changed the local variable "int gen2vm" to "bool gen2vm". Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1699691867-9827-1-git-send-email-ssengar@linux.microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.