On 11/19/2024 3:15 AM, Melody (Huibo) Wang wrote: > Hi Neeraj, > > On 9/13/2024 4:36 AM, Neeraj Upadhyay wrote: >> From: Kishon Vijay Abraham I <kvijayab@xxxxxxx> >> >> The Secure AVIC feature provides SEV-SNP guests hardware acceleration >> for performance sensitive APIC accesses while securely managing the >> guest-owned APIC state through the use of a private APIC backing page. >> This helps prevent malicious hypervisor from generating unexpected >> interrupts for a vCPU or otherwise violate architectural assumptions >> around APIC behavior. >> >> Add a new x2APIC driver that will serve as the base of the Secure AVIC >> support. It is initially the same as the x2APIC phys driver, but will be >> modified as features of Secure AVIC are implemented. >> >> Signed-off-by: Kishon Vijay Abraham I <kvijayab@xxxxxxx> >> Co-developed-by: Neeraj Upadhyay <Neeraj.Upadhyay@xxxxxxx> >> Signed-off-by: Neeraj Upadhyay <Neeraj.Upadhyay@xxxxxxx> >> --- >> arch/x86/Kconfig | 12 +++ >> arch/x86/boot/compressed/sev.c | 1 + >> arch/x86/coco/core.c | 3 + >> arch/x86/include/asm/msr-index.h | 4 +- >> arch/x86/kernel/apic/Makefile | 1 + >> arch/x86/kernel/apic/x2apic_savic.c | 112 ++++++++++++++++++++++++++++ >> include/linux/cc_platform.h | 8 ++ >> 7 files changed, 140 insertions(+), 1 deletion(-) >> create mode 100644 arch/x86/kernel/apic/x2apic_savic.c >> >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >> index 007bab9f2a0e..b05b4e9d2e49 100644 >> --- a/arch/x86/Kconfig >> +++ b/arch/x86/Kconfig >> @@ -469,6 +469,18 @@ config X86_X2APIC >> >> If you don't know what to do here, say N. >> >> +config AMD_SECURE_AVIC >> + bool "AMD Secure AVIC" >> + depends on X86_X2APIC && AMD_MEM_ENCRYPT > > If we remove the dependency on X2APIC, there are only 3 X2APIC functions which you call from this driver. Can we just expose them in the header, and then simply remove the dependency on X2APIC? > APIC common code (arch/x86/kernel/apic/apic.c) and other parts of the x86 code use X86_X2APIC config to enable x2apic related initialization and functionality. So, dependency on X2APIC need to be there. - Neeraj > Thanks > Melody >
