On Wed, Oct 12 2022, Gavin Shan <gs...@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. > > This improves the address assignment for those three high memory > region by skipping the address assignment for one specific high > memory region if it has been disabled in case (1), (2) and (3). > 'vms->high_compact' is false for now, meaning that we don't have > any behavior changes until it becomes configurable through property > 'compact-highmem' in next patch. > > Signed-off-by: Gavin Shan <gs...@redhat.com> > Tested-by: Zhenyu Zhang <zheny...@redhat.com> > --- > hw/arm/virt.c | 23 +++++++++++++++-------- > include/hw/arm/virt.h | 1 + > 2 files changed, 16 insertions(+), 8 deletions(-)
Reviewed-by: Cornelia Huck <coh...@redhat.com>