Without this, asking for 3.25G on memory for pc-i440fx-2.0 does not
adjust the pci hole to start at 3G. Asking for 3.75G does do this
adjustment.
Here is what the current code does:
out/x86_64-softmmu/qemu-system-x86_64 -serial pty ~/qemu-img/Lin-Net-disk1.raw
-machine pc-i440fx-2.0 -m 3.75G
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000bfffe000 (usable)
BIOS-e820: 00000000bfffe000 - 00000000c0000000 (reserved)
BIOS-e820: 00000000feffc000 - 00000000ff000000 (reserved)
BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved)
BIOS-e820: 0000000100000000 - 0000000130000000 (usable)
out/x86_64-softmmu/qemu-system-x86_64 -serial pty ~/qemu-img/Lin-Net-disk1.raw
-machine pc-i440fx-1.7 -m 3.75G
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000dfffe000 (usable)
BIOS-e820: 00000000dfffe000 - 00000000e0000000 (reserved)
BIOS-e820: 00000000feffc000 - 00000000ff000000 (reserved)
BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved)
BIOS-e820: 0000000100000000 - 0000000110000000 (usable)
out/x86_64-softmmu/qemu-system-x86_64 -serial pty ~/qemu-img/Lin-Net-disk1.raw
-machine pc-i440fx-2.0 -m 3.25G
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000cfffe000 (usable)
BIOS-e820: 00000000cfffe000 - 00000000d0000000 (reserved)
BIOS-e820: 00000000feffc000 - 00000000ff000000 (reserved)
BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved)
out/x86_64-softmmu/qemu-system-x86_64 -serial pty ~/qemu-img/Lin-Net-disk1.raw
-machine pc-i440fx-1.7 -m 3.25G
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000cfffe000 (usable)
BIOS-e820: 00000000cfffe000 - 00000000d0000000 (reserved)
BIOS-e820: 00000000feffc000 - 00000000ff000000 (reserved)
BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved)
After this patch:
out/x86_64-softmmu/qemu-system-x86_64 -serial pty ~/qemu-img/Lin-Net-disk1.raw
-machine pc-i440fx-2.0 -m 3.75G
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000bfffe000 (usable)
BIOS-e820: 00000000bfffe000 - 00000000c0000000 (reserved)
BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved)
BIOS-e820: 0000000100000000 - 0000000130000000 (usable)
out/x86_64-softmmu/qemu-system-x86_64 -serial pty ~/qemu-img/Lin-Net-disk1.raw
-machine pc-i440fx-1.7 -m 3.75G
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000dfffe000 (usable)
BIOS-e820: 00000000dfffe000 - 00000000e0000000 (reserved)
BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved)
BIOS-e820: 0000000100000000 - 0000000110000000 (usable)
out/x86_64-softmmu/qemu-system-x86_64 -serial pty ~/qemu-img/Lin-Net-disk1.raw
-machine pc-i440fx-2.0 -m 3.25G
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000bfffe000 (usable)
BIOS-e820: 00000000bfffe000 - 00000000c0000000 (reserved)
BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved)
BIOS-e820: 0000000100000000 - 0000000110000000 (usable)
out/x86_64-softmmu/qemu-system-x86_64 -serial pty ~/qemu-img/Lin-Net-disk1.raw
-machine pc-i440fx-1.7 -m 3.25G
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000cfffe000 (usable)
BIOS-e820: 00000000cfffe000 - 00000000d0000000 (reserved)
BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved)
Signed-off-by: Don Slutz <dsl...@verizon.com>
---
hw/i386/pc_piix.c | 13 ++++++++-----
hw/i386/pc_q35.c | 17 ++++++++++-------
2 files changed, 18 insertions(+), 12 deletions(-)
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index d5dc1ef..4e63d8f 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -95,6 +95,11 @@ static void pc_init1(QEMUMachineInitArgs *args,
DeviceState *icc_bridge;
FWCfgState *fw_cfg = NULL;
PcGuestInfo *guest_info;
+ /*
+ * For old machine types, use whatever split we used historically to avoid
+ * breaking migration.
+ */
+ ram_addr_t lowmem = gigabyte_align ? 0xc0000000 : 0xe0000000;
if (xen_enabled() && xen_hvm_init(&ram_memory) != 0) {
fprintf(stderr, "xen hardware virtual machine initialisation
failed\n");
@@ -111,15 +116,13 @@ static void pc_init1(QEMUMachineInitArgs *args,
kvmclock_create();
}
- /* Check whether RAM fits below 4G (leaving 1/2 GByte for IO memory).
+ /* Check whether RAM fits below 4G (leaving 1/2 GByte for IO memory (old)
+ * or 1 GByte for IO memory (new)).
* If it doesn't, we need to split it in chunks below and above 4G.
* In any case, try to make sure that guest addresses aligned at
* 1G boundaries get mapped to host addresses aligned at 1G boundaries.
- * For old machine types, use whatever split we used historically to avoid
- * breaking migration.
*/
- if (args->ram_size >= 0xe0000000) {
- ram_addr_t lowmem = gigabyte_align ? 0xc0000000 : 0xe0000000;
+ if (args->ram_size >= lowmem) {
above_4g_mem_size = args->ram_size - lowmem;
below_4g_mem_size = lowmem;
} else {
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index a7f6260..2627927 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -82,6 +82,11 @@ static void pc_q35_init(QEMUMachineInitArgs *args)
PCIDevice *ahci;
DeviceState *icc_bridge;
PcGuestInfo *guest_info;
+ /*
+ * For old machine types, use whatever split we used historically to avoid
+ * breaking migration.
+ */
+ ram_addr_t lowmem = gigabyte_align ? 0x80000000 : 0xb0000000;
if (xen_enabled() && xen_hvm_init(&ram_memory) != 0) {
fprintf(stderr, "xen hardware virtual machine initialisation
failed\n");
@@ -97,17 +102,15 @@ static void pc_q35_init(QEMUMachineInitArgs *args)
kvmclock_create();
- /* Check whether RAM fits below 4G (leaving 1/2 GByte for IO memory
- * and 256 Mbytes for PCI Express Enhanced Configuration Access Mapping
- * also known as MMCFG).
+ /* Check whether RAM fits below 4G (leaving 1 and 3/8 GByte for
+ * IO memory and 256 Mbytes for PCI Express Enhanced
+ * Configuration Access Mapping also known as MMCFG (old) or
+ * leaving 2 GByte for IO memory (new)).
* If it doesn't, we need to split it in chunks below and above 4G.
* In any case, try to make sure that guest addresses aligned at
* 1G boundaries get mapped to host addresses aligned at 1G boundaries.
- * For old machine types, use whatever split we used historically to avoid
- * breaking migration.
*/
- if (args->ram_size >= 0xb0000000) {
- ram_addr_t lowmem = gigabyte_align ? 0x80000000 : 0xb0000000;
+ if (args->ram_size >= lowmem) {
above_4g_mem_size = args->ram_size - lowmem;
below_4g_mem_size = lowmem;
} else {
--
1.8.4
