ShuriZma
/
xemu
mirror of https://github.com/xemu-project/xemu.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

virt-acpi-build: add always-on property for timer 

This patch is the ACPI equivalent of "hw/arm/virt: Add always-on
property to the virt board timer". The timer is always on, and
thus setting this informs Linux that it may switch off the periodic
timer. Switching off the periodic timer substantially reduces the
number of interrupts the host needs to inject.

Testing note: AArch64 guests (the only ones currently booting with
ACPI) do not actually need this patch to determine it can turn the
periodic timer off. I therefore used a hacked guest kernel to ensure
this patch works as the equivalent DT patch does.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Shannon Zhao <shannon.zhao@linaro.org>
Message-id: 1453380893-26174-1-git-send-email-drjones@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Andrew Jones 2016-02-03 13:46:32 +00:00 committed by Peter Maydell
parent 87574621b1
commit a43e68a08b
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
hw/arm/virt-acpi-build.c
View File

@ -443,7 +443,7 @@ build_gtdt(GArray *table_data, GArray *linker)
gtdt->secure_el1_flags = ACPI_EDGE_SENSITIVE;
gtdt->non_secure_el1_interrupt = ARCH_TIMER_NS_EL1_IRQ + 16;
gtdt->non_secure_el1_flags = ACPI_EDGE_SENSITIVE;
gtdt->non_secure_el1_flags = ACPI_EDGE_SENSITIVE | ACPI_GTDT_ALWAYS_ON;
gtdt->virtual_timer_interrupt = ARCH_TIMER_VIRT_IRQ + 16;
gtdt->virtual_timer_flags = ACPI_EDGE_SENSITIVE;