| Message ID | 20220921231349.274049-1-gshan@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | hw/arm/virt: Improve address assignment for high memory regions | expand |
[PATCH v3 0/5] hw/arm/virt: Improve address assignment for high memory regions
Author: Gavin Shan <gshan@redhat.com>
Date: Thu Sep 22 07:13:45 2022 +0800
PATCH[1-3] preparatory work for the improvment
PATCH[4] improve high memory region address assignment
PATCH[5] adds 'highmem-compact' to enable or disable the optimization
Signed-off-by: Gavin Shan <gshan@redhat.com>
The patchs works well on "IPA Size Limit: 40" FUJITSU machine.
I added some debug code to show high memory region address.
The test results are as expected.
1. virt-7.2 default
# /home/qemu/build/qemu-system-aarch64 -accel kvm -cpu host -machine
virt-7.2 -m 4G,maxmem=511G -monitor stdio
=====> virt_set_high_memmap: pa_bits=40, base=0x8000000000
[HIGH_GIC_REDIST2]: disabled, highest_gpa=0x7fffffffff [no] [yes]
[HIGH_PCIE_ECAM]: disabled, highest_gpa=0x7fffffffff [no] [yes]
[HIGH_PCIE_MMIO] enabled, highest_gpa=0xffffffffff
2. When virt-7.2,highmem-compact=off
# /home/qemu/build/qemu-system-aarch64 -accel kvm -cpu host -machine
virt-7.2,highmem-compact=off -m 4G,maxmem=511G -monitor stdio
=====> virt_set_high_memmap: pa_bits=40, base=0x8000000000
[HIGH_GIC_REDIST2]: disabled, highest_gpa=0x8003ffffff [no] [yes]
[HIGH_PCIE_ECAM]: disabled, highest_gpa=0x801fffffff [no] [yes]
[HIGH_PCIE_MMIO]: disabled, highest_gpa=0x801fffffff [no] [no]
3. virt-7.1 default
# /home/qemu/build/qemu-system-aarch64 -accel kvm -cpu host -machine
virt-7.1 -m 4G,maxmem=511G -monitor stdio
=====> virt_set_high_memmap: pa_bits=40, base=0x8000000000
[HIGH_GIC_REDIST2]: disabled, highest_gpa=0x8003ffffff [no] [yes]
[HIGH_PCIE_ECAM]: disabled, highest_gpa=0x801fffffff [no] [yes]
[HIGH_PCIE_MMIO]: disabled, highest_gpa=0x801fffffff [no] [no]
2. When virt-7.1,highmem-compact=on
# /home/qemu/build/qemu-system-aarch64 -accel kvm -cpu host -machine
virt-7.1,highmem-compact=on -m 4G,maxmem=511G -monitor stdio
=====> virt_set_high_memmap: pa_bits=40, base=0x8000000000
[HIGH_GIC_REDIST2]: disabled, highest_gpa=0x7fffffffff [no] [yes]
[HIGH_PCIE_ECAM]: disabled, highest_gpa=0x7fffffffff [no] [yes]
[HIGH_PCIE_MMIO] enabled, highest_gpa=0xffffffffff
Tested-by: Zhenyu Zhang<zhenyzha@redhat.com>
On Thu, Sep 22, 2022 at 7:13 AM Gavin Shan <gshan@redhat.com> wrote:
>
> There are three high memory regions, which are VIRT_HIGH_REDIST2,
> VIRT_HIGH_PCIE_ECAM and VIRT_HIGH_PCIE_MMIO. Their base addresses
> are floating on highest RAM address. However, they can be disabled
> in several cases.
>
> (1) One specific high memory region is disabled by developer by
> toggling vms->highmem_{redists, ecam, mmio}.
>
> (2) VIRT_HIGH_PCIE_ECAM region is disabled on machine, which is
> 'virt-2.12' or ealier than it.
>
> (3) VIRT_HIGH_PCIE_ECAM region is disabled when firmware is loaded
> on 32-bits system.
>
> (4) One specific high memory region is disabled when it breaks the
> PA space limit.
>
> The current implementation of virt_set_memmap() isn't comprehensive
> because the space for one specific high memory region is always
> reserved from the PA space for case (1), (2) and (3). In the code,
> 'base' and 'vms->highest_gpa' are always increased for those three
> cases. It's unnecessary since the assigned space of the disabled
> high memory region won't be used afterwards.
>
> The series intends to improve the address assignment for these
> high memory regions.
>
> PATCH[1-3] preparatory work for the improvment
> PATCH[4] improve high memory region address assignment
> PATCH[5] adds 'highmem-compact' to enable or disable the optimization
>
> History
> =======
> v2: https://lore.kernel.org/all/20220815062958.100366-1-gshan@redhat.com/T/
> v1: https://lists.nongnu.org/archive/html/qemu-arm/2022-08/msg00013.html
>
> Changelog
> ==========
> v3:
> * Reorder the patches (Gavin)
> * Add 'highmem-compact' property for backwards compatibility (Eric)
> v2:
> * Split the patches for easier review (Gavin)
> * Improved changelog (Marc)
> * Use 'bool fits' in virt_set_high_memmap() (Eric)
>
> Gavin Shan (5):
> hw/arm/virt: Introduce virt_set_high_memmap() helper
> hw/arm/virt: Rename variable size to region_size in
> virt_set_high_memmap()
> hw/arm/virt: Introduce variable region_base in virt_set_high_memmap()
> hw/arm/virt: Improve high memory region address assignment
> hw/arm/virt: Add 'highmem-compact' property
>
> docs/system/arm/virt.rst | 4 ++
> hw/arm/virt.c | 116 ++++++++++++++++++++++++++++-----------
> include/hw/arm/virt.h | 2 +
> 3 files changed, 89 insertions(+), 33 deletions(-)
>
> --
> 2.23.0
>
There are three high memory regions, which are VIRT_HIGH_REDIST2, VIRT_HIGH_PCIE_ECAM and VIRT_HIGH_PCIE_MMIO. Their base addresses are floating on highest RAM address. However, they can be disabled in several cases. (1) One specific high memory region is disabled by developer by toggling vms->highmem_{redists, ecam, mmio}. (2) VIRT_HIGH_PCIE_ECAM region is disabled on machine, which is 'virt-2.12' or ealier than it. (3) VIRT_HIGH_PCIE_ECAM region is disabled when firmware is loaded on 32-bits system. (4) One specific high memory region is disabled when it breaks the PA space limit. The current implementation of virt_set_memmap() isn't comprehensive because the space for one specific high memory region is always reserved from the PA space for case (1), (2) and (3). In the code, 'base' and 'vms->highest_gpa' are always increased for those three cases. It's unnecessary since the assigned space of the disabled high memory region won't be used afterwards. The series intends to improve the address assignment for these high memory regions. PATCH[1-3] preparatory work for the improvment PATCH[4] improve high memory region address assignment PATCH[5] adds 'highmem-compact' to enable or disable the optimization History ======= v2: https://lore.kernel.org/all/20220815062958.100366-1-gshan@redhat.com/T/ v1: https://lists.nongnu.org/archive/html/qemu-arm/2022-08/msg00013.html Changelog ========== v3: * Reorder the patches (Gavin) * Add 'highmem-compact' property for backwards compatibility (Eric) v2: * Split the patches for easier review (Gavin) * Improved changelog (Marc) * Use 'bool fits' in virt_set_high_memmap() (Eric) Gavin Shan (5): hw/arm/virt: Introduce virt_set_high_memmap() helper hw/arm/virt: Rename variable size to region_size in virt_set_high_memmap() hw/arm/virt: Introduce variable region_base in virt_set_high_memmap() hw/arm/virt: Improve high memory region address assignment hw/arm/virt: Add 'highmem-compact' property docs/system/arm/virt.rst | 4 ++ hw/arm/virt.c | 116 ++++++++++++++++++++++++++++----------- include/hw/arm/virt.h | 2 + 3 files changed, 89 insertions(+), 33 deletions(-)