From 121d96b903b221e2c63fa0fc5a8901dc24645a47 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Wed, 31 Jul 2024 16:35:31 +0100 Subject: [cpuid] Allow reading hypervisor CPUID leaves Hypervisors typically intercept CPUID leaves in the range 0x40000000 to 0x400000ff, with leaf 0x40000000 returning the maximum supported function within this range in register %eax. iPXE currently masks off bit 30 from the requested CPUID leaf when checking to see if a function is supported, which causes this check to read from leaf 0x00000000 instead of 0x40000000. Fix by including bit 30 within the mask. Signed-off-by: Michael Brown --- src/arch/x86/include/ipxe/cpuid.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'src/arch/x86/include') diff --git a/src/arch/x86/include/ipxe/cpuid.h b/src/arch/x86/include/ipxe/cpuid.h index 90d1bf01d..99b91c5c8 100644 --- a/src/arch/x86/include/ipxe/cpuid.h +++ b/src/arch/x86/include/ipxe/cpuid.h @@ -33,6 +33,9 @@ struct x86_features { /** CPUID extended function */ #define CPUID_EXTENDED 0x80000000UL +/** CPUID hypervisor function */ +#define CPUID_HYPERVISOR 0x40000000UL + /** Get vendor ID and largest standard function */ #define CPUID_VENDOR_ID 0x00000000UL -- cgit