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authorMarc Zyngier <[email protected]>2024-02-22 14:12:09 +0000
committerOliver Upton <[email protected]>2024-02-22 18:13:53 +0000
commit99101dda29e3186b1356b0dc4dbb835c02c71ac9 (patch)
tree3a73cceb7f57a143fb732adf31fe015a1b446a4f
parent891766581deaf84919911c6a046592ce0ac49bc6 (diff)
KVM: arm64: Make build-time check of RES0/RES1 bits optional
In order to ease the transition towards a state of absolute paranoia where all RES0/RES1 bits gets checked against what KVM know of them, make the checks optional and guarded by a config symbol (CONFIG_KVM_ARM64_RES_BITS_PARANOIA) default to n. Signed-off-by: Marc Zyngier <[email protected]> Link: https://lore.kernel.org/kvm/[email protected]/ Signed-off-by: Oliver Upton <[email protected]>
-rw-r--r--arch/arm64/kvm/Kconfig11
-rw-r--r--arch/arm64/kvm/check-res-bits.h4
2 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 5c2a672c06a8..fa9389270cfe 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -67,4 +67,15 @@ config PROTECTED_NVHE_STACKTRACE
If unsure, or not using protected nVHE (pKVM), say N.
+config KVM_ARM64_RES_BITS_PARANOIA
+ bool "Build-time check of RES0/RES1 bits"
+ depends on KVM
+ default n
+ help
+ Say Y here to validate that KVM's knowledge of most system
+ registers' RES0/RES1 bits matches when the rest of the kernel
+ defines. Expect the build to fail badly if you enable this.
+
+ Just say N.
+
endif # VIRTUALIZATION
diff --git a/arch/arm64/kvm/check-res-bits.h b/arch/arm64/kvm/check-res-bits.h
index 967b5d171d53..2d98e60efc3c 100644
--- a/arch/arm64/kvm/check-res-bits.h
+++ b/arch/arm64/kvm/check-res-bits.h
@@ -21,6 +21,8 @@
*/
static inline void check_res_bits(void)
{
+#ifdef CONFIG_KVM_ARM64_RES_BITS_PARANOIA
+
BUILD_BUG_ON(OSDTRRX_EL1_RES0 != (GENMASK_ULL(63, 32)));
BUILD_BUG_ON(MDCCINT_EL1_RES0 != (GENMASK_ULL(63, 31) | GENMASK_ULL(28, 0)));
BUILD_BUG_ON(MDSCR_EL1_RES0 != (GENMASK_ULL(63, 36) | GENMASK_ULL(28, 28) | GENMASK_ULL(25, 24) | GENMASK_ULL(20, 20) | GENMASK_ULL(18, 16) | GENMASK_ULL(11, 7) | GENMASK_ULL(5, 1)));
@@ -118,4 +120,6 @@ static inline void check_res_bits(void)
BUILD_BUG_ON(TRBMAR_EL1_RES0 != (GENMASK_ULL(63, 12)));
BUILD_BUG_ON(TRBTRG_EL1_RES0 != (GENMASK_ULL(63, 32)));
BUILD_BUG_ON(TRBIDR_EL1_RES0 != (GENMASK_ULL(63, 12) | GENMASK_ULL(7, 6)));
+
+#endif
}