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* memory: alloc RAM from file at offsetJagannathan Raman2021-02-091-1/+3
| | | | | | | | | | | | | Allow RAM MemoryRegion to be created from an offset in a file, instead of allocating at offset of 0 by default. This is needed to synchronize RAM between QEMU & remote process. Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Signed-off-by: John G Johnson <john.g.johnson@oracle.com> Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 609996697ad8617e3b01df38accc5c208c24d74e.1611938319.git.jag.raman@oracle.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* memory: add readonly support to memory_region_init_ram_from_file()Stefan Hajnoczi2021-02-011-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is currently no way to open(O_RDONLY) and mmap(PROT_READ) when creating a memory region from a file. This functionality is needed since the underlying host file may not allow writing. Add a bool readonly argument to memory_region_init_ram_from_file() and the APIs it calls. Extend memory_region_init_ram_from_file() rather than introducing a memory_region_init_rom_from_file() API so that callers can easily make a choice between read/write and read-only at runtime without calling different APIs. No new RAMBlock flag is introduced for read-only because it's unclear whether RAMBlocks need to know that they are read-only. Pass a bool readonly argument instead. Both of these design decisions can be changed in the future. It just seemed like the simplest approach to me. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Message-Id: <20210104171320.575838-2-stefanha@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
* Include qemu-common.h exactly where neededMarkus Armbruster2019-06-121-1/+0Star
| | | | | | | | | | | | | | | | No header includes qemu-common.h after this commit, as prescribed by qemu-common.h's file comment. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190523143508.25387-5-armbru@redhat.com> [Rebased with conflicts resolved automatically, except for include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and net/tap-bsd.c fixed up]
* util/mmap-alloc: Add a 'is_pmem' parameter to qemu_ram_mmapZhang Yi2019-04-251-1/+20
| | | | | | | | | | | | | | besides the existing 'shared' flags, we are going to add 'is_pmem' to qemu_ram_mmap(), which indicated the memory backend file is a persist memory. Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com> Reviewed-by: Pankaj Gupta <pagupta@redhat.com> Message-Id: <786c46862cfeb253ee0ea2f44d62ffe76edb7fa4.1549555521.git.yi.z.zhang@linux.intel.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Pankaj Gupta <pagupta@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
* mmap-alloc: fix hugetlbfs misaligned length in ppc64Murilo Opsfelder Araujo2019-02-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 7197fb4058bcb68986bae2bb2c04d6370f3e7218 ("util/mmap-alloc: fix hugetlb support on ppc64") fixed Huge TLB mappings on ppc64. However, we still need to consider the underlying huge page size during munmap() because it requires that both address and length be a multiple of the underlying huge page size for Huge TLB mappings. Quote from "Huge page (Huge TLB) mappings" paragraph under NOTES section of the munmap(2) manual: "For munmap(), addr and length must both be a multiple of the underlying huge page size." On ppc64, the munmap() in qemu_ram_munmap() does not work for Huge TLB mappings because the mapped segment can be aligned with the underlying huge page size, not aligned with the native system page size, as returned by getpagesize(). This has the side effect of not releasing huge pages back to the pool after a hugetlbfs file-backed memory device is hot-unplugged. This patch fixes the situation in qemu_ram_mmap() and qemu_ram_munmap() by considering the underlying page size on ppc64. After this patch, memory hot-unplug releases huge pages back to the pool. Fixes: 7197fb4058bcb68986bae2bb2c04d6370f3e7218 Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Reviewed-by: Greg Kurz <groug@kaod.org> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
* exec, kvm, target-ppc: Move getrampagesize() to common codeAlexey Kardashevskiy2017-03-031-0/+2
| | | | | | | | | | | | | | | | getrampagesize() returns the largest supported page size and mainly used to know if huge pages are enabled. However is implemented in target-ppc/kvm.c and not available in TCG or other architectures. This renames and moves gethugepagesize() to mmap-alloc.c where fd-based analog of it is already implemented. This renames and moves getrampagesize() to exec.c as it seems to be the common place for helpers like this. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
* Clean up ill-advised or unusual header guardsMarkus Armbruster2016-07-121-2/+2
| | | | | | | Cleaned up with scripts/clean-header-guards.pl. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Richard Henderson <rth@twiddle.net>
* util/mmap-alloc: fix hugetlb support on ppc64Michael S. Tsirkin2015-12-021-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 8561c9244ddf1122d "exec: allocate PROT_NONE pages on top of RAM", it is no longer possible to back guest RAM with hugepages on ppc64 hosts: mmap(NULL, 285212672, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x3fff57000000 mmap(0x3fff57000000, 268435456, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 19, 0) = -1 EBUSY (Device or resource busy) This is because on ppc64, Linux fixes a page size for a virtual address at mmap time, so we can't switch a range of memory from anonymous small pages to hugetlbs with MAP_FIXED. See commit d0f13e3c20b6fb73ccb467bdca97fa7cf5a574cd ("[POWERPC] Introduce address space "slices"") in Linux history for the details. Detect this and create the PROT_NONE mapping using the same fd. Naturally, this makes the guard page bigger with hugetlbfs. Based on patch by Greg Kurz. Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* exec: factor out duplicate mmap codeMichael S. Tsirkin2015-10-211-0/+10
Anonymous and file-backed RAM allocation are now almost exactly the same. Reduce code duplication by moving RAM mmap code out of oslib-posix.c and exec.c. Reported-by: Marc-André Lureau <mlureau@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Tested-by: Thibaut Collet <thibaut.collet@6wind.com>