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[Qemu-devel] [PULL 05/36] hw/i386/pc: Map into memory the initrd
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 05/36] hw/i386/pc: Map into memory the initrd |
Date: |
Tue, 20 Aug 2019 08:59:24 +0200 |
From: Stefano Garzarella <address@hidden>
In order to reduce the memory footprint we map into memory
the initrd using g_mapped_file_new() instead of reading it.
In this way we can share the initrd pages between multiple
instances of QEMU.
Suggested-by: Paolo Bonzini <address@hidden>
Signed-off-by: Stefano Garzarella <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
hw/i386/pc.c | 17 +++++++++++++----
include/hw/i386/pc.h | 1 +
2 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 549c437..96f6b89 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1241,17 +1241,21 @@ static void load_linux(PCMachineState *pcms,
/* load initrd */
if (initrd_filename) {
+ GMappedFile *mapped_file;
gsize initrd_size;
gchar *initrd_data;
GError *gerr = NULL;
- if (!g_file_get_contents(initrd_filename, &initrd_data,
- &initrd_size, &gerr)) {
+ mapped_file = g_mapped_file_new(initrd_filename, false, &gerr);
+ if (!mapped_file) {
fprintf(stderr, "qemu: error reading initrd %s: %s\n",
initrd_filename, gerr->message);
exit(1);
}
+ pcms->initrd_mapped_file = mapped_file;
+ initrd_data = g_mapped_file_get_contents(mapped_file);
+ initrd_size = g_mapped_file_get_length(mapped_file);
initrd_max = pcms->below_4g_mem_size - pcmc->acpi_data_size -
1;
if (initrd_size >= initrd_max) {
fprintf(stderr, "qemu: initrd is too large, cannot
support."
@@ -1378,6 +1382,7 @@ static void load_linux(PCMachineState *pcms,
/* load initrd */
if (initrd_filename) {
+ GMappedFile *mapped_file;
gsize initrd_size;
gchar *initrd_data;
GError *gerr = NULL;
@@ -1387,12 +1392,16 @@ static void load_linux(PCMachineState *pcms,
exit(1);
}
- if (!g_file_get_contents(initrd_filename, &initrd_data,
- &initrd_size, &gerr)) {
+ mapped_file = g_mapped_file_new(initrd_filename, false, &gerr);
+ if (!mapped_file) {
fprintf(stderr, "qemu: error reading initrd %s: %s\n",
initrd_filename, gerr->message);
exit(1);
}
+ pcms->initrd_mapped_file = mapped_file;
+
+ initrd_data = g_mapped_file_get_contents(mapped_file);
+ initrd_size = g_mapped_file_get_length(mapped_file);
if (initrd_size >= initrd_max) {
fprintf(stderr, "qemu: initrd is too large, cannot support."
"(max: %"PRIu32", need %"PRId64")\n",
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 859b64c..44edc69 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -42,6 +42,7 @@ struct PCMachineState {
FWCfgState *fw_cfg;
qemu_irq *gsi;
PFlashCFI01 *flash[2];
+ GMappedFile *initrd_mapped_file;
/* Configuration options: */
uint64_t max_ram_below_4g;
--
1.8.3.1
- [Qemu-devel] [PULL 00/36] QEMU patches for 2018-08-20, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 01/36] kvm: i386: halt poll control MSR support, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 02/36] target-i386: adds PV_SCHED_YIELD CPUID feature bit, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 03/36] loader: Handle memory-mapped ELFs, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 04/36] elf-ops.h: Map into memory the ELF to load, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 05/36] hw/i386/pc: Map into memory the initrd,
Paolo Bonzini <=
- [Qemu-devel] [PULL 07/36] configure: Define target access alignment in configure, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 06/36] memory: assert on out of scope notification, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 08/36] block: fix NetBSD qemu-iotests failure, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 10/36] target-i386: kvm: 'kvm_get_supported_msrs' cleanup, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 11/36] test-throttle: Fix uninitialized use of burst_length, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 09/36] 9p: simplify source file selection, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 13/36] i386/kvm: initialize struct at full before ioctl call, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 21/36] replay: add missing fix for internal function, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 24/36] replay: fix replay shutdown, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 22/36] replay: document development rules, Paolo Bonzini, 2019/08/20