From f4c0490cc3990b175d070e763a9c19b17ec341f7 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Mon, 6 Jan 2014 17:38:37 +0000 Subject: [PATCH] kvm tools: arm: add option to override generic timer frequency Some platforms have secure firmware which does not correctly set the CNTFRQ register on boot, preventing the use of the Generic Timer. This patch allows mirroring the necessary host workaround by specifying the clock-frequency property in the guest DT. This should only be considered a means of KVM bring-up on such systems, such that vendors may be convinced to properly implement their firmware to support the virtualisation capabilities of their hardware. Acked-by: Will Deacon Signed-off-by: Robin Murphy Signed-off-by: Will Deacon Signed-off-by: Pekka Enberg --- arm/include/arm-common/kvm-config-arch.h | 15 ++++++++++----- arm/timer.c | 3 +++ 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/arm/include/arm-common/kvm-config-arch.h b/arm/include/arm-common/kvm-config-arch.h index 7ac6f6e..f3baf39 100644 --- a/arm/include/arm-common/kvm-config-arch.h +++ b/arm/include/arm-common/kvm-config-arch.h @@ -5,13 +5,18 @@ struct kvm_config_arch { const char *dump_dtb_filename; + unsigned int force_cntfrq; bool aarch32_guest; }; -#define OPT_ARCH_RUN(pfx, cfg) \ - pfx, \ - ARM_OPT_ARCH_RUN(cfg) \ - OPT_STRING('\0', "dump-dtb", &(cfg)->dump_dtb_filename, \ - ".dtb file", "Dump generated .dtb to specified file"), +#define OPT_ARCH_RUN(pfx, cfg) \ + pfx, \ + ARM_OPT_ARCH_RUN(cfg) \ + OPT_STRING('\0', "dump-dtb", &(cfg)->dump_dtb_filename, \ + ".dtb file", "Dump generated .dtb to specified file"), \ + OPT_UINTEGER('\0', "override-bad-firmware-cntfrq", &(cfg)->force_cntfrq,\ + "Specify Generic Timer frequency in guest DT to " \ + "work around buggy secure firmware *Firmware should be " \ + "updated to program CNTFRQ correctly*"), #endif /* ARM_COMMON__KVM_CONFIG_ARCH_H */ diff --git a/arm/timer.c b/arm/timer.c index e31faae..d757c1d 100644 --- a/arm/timer.c +++ b/arm/timer.c @@ -33,5 +33,8 @@ void timer__generate_fdt_nodes(void *fdt, struct kvm *kvm, int *irqs) _FDT(fdt_begin_node(fdt, "timer")); _FDT(fdt_property(fdt, "compatible", compatible, sizeof(compatible))); _FDT(fdt_property(fdt, "interrupts", irq_prop, sizeof(irq_prop))); + if (kvm->cfg.arch.force_cntfrq > 0) + _FDT(fdt_property_cell(fdt, "clock-frequency", kvm->cfg.arch.force_cntfrq)); _FDT(fdt_end_node(fdt)); } +