From e502fe96ac4343a3f4a3c13f28eea03ae7b11c3f Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Wed, 24 Jul 2019 16:31:05 +0200 Subject: [PATCH] hw/i386/pc: Map into memory the initrd 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 Signed-off-by: Stefano Garzarella Message-Id: <20190724143105.307042-4-sgarzare@redhat.com> Signed-off-by: Paolo Bonzini --- 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 3ab4bcb3ca..6b4f32edfe 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1244,17 +1244,21 @@ 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." @@ -1381,6 +1385,7 @@ static void load_linux(PCMachineState *pcms, /* load initrd */ if (initrd_filename) { + GMappedFile *mapped_file; gsize initrd_size; gchar *initrd_data; GError *gerr = NULL; @@ -1390,12 +1395,16 @@ 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 4bb9e29114..2afe285009 100644 --- a/include/hw/i386/pc.h +++ b/include/hw/i386/pc.h @@ -41,6 +41,7 @@ struct PCMachineState { FWCfgState *fw_cfg; qemu_irq *gsi; PFlashCFI01 *flash[2]; + GMappedFile *initrd_mapped_file; /* Configuration options: */ uint64_t max_ram_below_4g; -- 2.11.4.GIT