linux-kernel - [PATCH v4 04/15] arm64: kvm: Use build-time defines in has

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 25 Jun 2020 14:14:09 +0100
From:   David Brazdil <dbrazdil@...gle.com>
To:     Marc Zyngier <maz@...nel.org>, Will Deacon <will@...nel.org>,
        Catalin Marinas <catalin.marinas@....com>,
        James Morse <james.morse@....com>,
        Julien Thierry <julien.thierry.kdev@...il.com>,
        Suzuki K Poulose <suzuki.poulose@....com>
Cc:     kvmarm@...ts.cs.columbia.edu, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, android-kvm@...gle.com,
        kernel-team@...roid.com, David Brazdil <dbrazdil@...gle.com>
Subject: [PATCH v4 04/15] arm64: kvm: Use build-time defines in has_vhe()

Build system compiles hyp code with macros specifying if the code belongs
to VHE or nVHE. Use these macros to evaluate has_vhe() at compile time.

Signed-off-by: David Brazdil <dbrazdil@...gle.com>
---
 arch/arm64/include/asm/virt.h | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index 5051b388c654..09977acc007d 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -85,10 +85,17 @@ static inline bool is_kernel_in_hyp_mode(void)
 
 static __always_inline bool has_vhe(void)
 {
-	if (cpus_have_final_cap(ARM64_HAS_VIRT_HOST_EXTN))
+	/*
+	 * The following macros are defined for code specic to VHE/nVHE.
+	 * If has_vhe() is inlined into those compilation units, it can
+	 * be determined statically. Otherwise fall back to caps.
+	 */
+	if (__is_defined(__KVM_VHE_HYPERVISOR__))
 		return true;
-
-	return false;
+	else if (__is_defined(__KVM_NVHE_HYPERVISOR__))
+		return false;
+	else
+		return cpus_have_final_cap(ARM64_HAS_VIRT_HOST_EXTN);
 }
 
 #endif /* __ASSEMBLY__ */
-- 
2.27.0