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authorAndrew Jones <drjones@redhat.com>2016-02-03 13:46:32 +0000
committerTimothy Pearson <tpearson@raptorengineering.com>2019-11-29 19:31:25 -0600
commitbdd44c274d78efeeadb8fe38d881e73e044b728a (patch)
tree842e2260b5c94ce791733f7ba9e79c95e7742a41
parent6786e437b69bfe26f70c9c26a4c3dcfa841fb18b (diff)
downloadhqemu-bdd44c274d78efeeadb8fe38d881e73e044b728a.zip
hqemu-bdd44c274d78efeeadb8fe38d881e73e044b728a.tar.gz
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>
-rw-r--r--hw/arm/virt-acpi-build.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 87fbe7c..f6e538f 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -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;
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