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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /tools/testing/selftests/kvm/lib/x86_64/apic.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/kvm/lib/x86_64/apic.c')
-rw-r--r--tools/testing/selftests/kvm/lib/x86_64/apic.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/lib/x86_64/apic.c b/tools/testing/selftests/kvm/lib/x86_64/apic.c
new file mode 100644
index 000000000..7168e25c1
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/x86_64/apic.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * tools/testing/selftests/kvm/lib/x86_64/processor.c
+ *
+ * Copyright (C) 2021, Google LLC.
+ */
+
+#include "apic.h"
+
+void apic_disable(void)
+{
+ wrmsr(MSR_IA32_APICBASE,
+ rdmsr(MSR_IA32_APICBASE) &
+ ~(MSR_IA32_APICBASE_ENABLE | MSR_IA32_APICBASE_EXTD));
+}
+
+void xapic_enable(void)
+{
+ uint64_t val = rdmsr(MSR_IA32_APICBASE);
+
+ /* Per SDM: to enable xAPIC when in x2APIC must first disable APIC */
+ if (val & MSR_IA32_APICBASE_EXTD) {
+ apic_disable();
+ wrmsr(MSR_IA32_APICBASE,
+ rdmsr(MSR_IA32_APICBASE) | MSR_IA32_APICBASE_ENABLE);
+ } else if (!(val & MSR_IA32_APICBASE_ENABLE)) {
+ wrmsr(MSR_IA32_APICBASE, val | MSR_IA32_APICBASE_ENABLE);
+ }
+
+ /*
+ * Per SDM: reset value of spurious interrupt vector register has the
+ * APIC software enabled bit=0. It must be enabled in addition to the
+ * enable bit in the MSR.
+ */
+ val = xapic_read_reg(APIC_SPIV) | APIC_SPIV_APIC_ENABLED;
+ xapic_write_reg(APIC_SPIV, val);
+}
+
+void x2apic_enable(void)
+{
+ wrmsr(MSR_IA32_APICBASE, rdmsr(MSR_IA32_APICBASE) |
+ MSR_IA32_APICBASE_ENABLE | MSR_IA32_APICBASE_EXTD);
+ x2apic_write_reg(APIC_SPIV,
+ x2apic_read_reg(APIC_SPIV) | APIC_SPIV_APIC_ENABLED);
+}