From 37e14d976a8b2f5c35fdfa8b3726b60005545d0c Mon Sep 17 00:00:00 2001 From: Chen Qun Date: Mon, 7 Sep 2020 14:07:07 +0800 Subject: [PATCH] target/arm: ignore evtstrm and cpuid CPU features evtstrm and cpuid cann't be controlled by VMM: 1. evtstrm: The generic timer is configured to generate events at a frequency of approximately 100KHz. It's controlled by the linux kernel config CONFIG_ARM_ARCH_TIMER_EVTSTREAM. 2. cpuid: EL0 access to certain ID registers is available. It's always set by linux kernel after 77c97b4ee2129 ("arm64: cpufeature: Expose CPUID registers by emulation"). However, they are exposed by getauxval() and /proc/cpuinfo. Hence, let's report and ignore the CPU features if someone set them. Signed-off-by: Peng Liang Signed-off-by: Dongxu Sun --- ...gnore-evtstrm-and-cpuid-CPU-features.patch | 67 +++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 target-arm-ignore-evtstrm-and-cpuid-CPU-features.patch diff --git a/target-arm-ignore-evtstrm-and-cpuid-CPU-features.patch b/target-arm-ignore-evtstrm-and-cpuid-CPU-features.patch new file mode 100644 index 0000000..edb4ea4 --- /dev/null +++ b/target-arm-ignore-evtstrm-and-cpuid-CPU-features.patch @@ -0,0 +1,67 @@ +From 4558dc5590b89b1252baea2734c2b3668566e5cb Mon Sep 17 00:00:00 2001 +From: Peng Liang +Date: Mon, 7 Sep 2020 14:07:07 +0800 +Subject: [PATCH] target/arm: ignore evtstrm and cpuid CPU features + +evtstrm and cpuid cann't be controlled by VMM: +1. evtstrm: The generic timer is configured to generate events at a + frequency of approximately 100KHz. It's controlled by the linux + kernel config CONFIG_ARM_ARCH_TIMER_EVTSTREAM. +2. cpuid: EL0 access to certain ID registers is available. It's always + set by linux kernel after 77c97b4ee2129 ("arm64: cpufeature: Expose + CPUID registers by emulation"). +However, they are exposed by getauxval() and /proc/cpuinfo. Hence, +let's report and ignore the CPU features if someone set them. + +Signed-off-by: Peng Liang +Signed-off-by: Dongxu Sun +--- + target/arm/cpu64.c | 29 ++++++++++++++++++++++++++++- + 1 file changed, 28 insertions(+), 1 deletion(-) + +diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c +index 9e5179afbe..287e7ac91c 100644 +--- a/target/arm/cpu64.c ++++ b/target/arm/cpu64.c +@@ -982,10 +982,37 @@ static gchar *aarch64_gdb_arch_name(CPUState *cs) + return g_strdup("aarch64"); + } + ++static const char *unconfigurable_feats[] = { ++ "evtstrm", ++ "cpuid", ++ NULL ++}; ++ ++static bool is_configurable_feat(const char *name) ++{ ++ int i; ++ ++ for (i = 0; unconfigurable_feats[i]; ++i) { ++ if (g_strcmp0(unconfigurable_feats[i], name) == 0) { ++ return false; ++ } ++ } ++ ++ return true; ++} ++ + static void + cpu_add_feat_as_prop(const char *typename, const char *name, const char *val) + { +- GlobalProperty *prop = g_new0(typeof(*prop), 1); ++ GlobalProperty *prop; ++ ++ if (!is_configurable_feat(name)) { ++ info_report("CPU feature '%s' is not configurable by QEMU. Ignore it.", ++ name); ++ return; ++ } ++ ++ prop = g_new0(typeof(*prop), 1); + prop->driver = typename; + prop->property = g_strdup(name); + prop->value = g_strdup(val); +-- +2.27.0 +