Re: [PATCH] sev-snp: parse MP tables for VMware hypervisor

From: Tom Lendacky
Date: Mon Mar 10 2025 - 09:15:13 EST


On 3/10/25 05:26, Borislav Petkov wrote:
> On Thu, Dec 19, 2024 at 11:44:00AM +0000, Ajay Kaher wrote:
>> For VMware hypervisor, SEV-SNP enabled VM's could boot without UEFI.
>> In this case, mpparse_find_mptable() has to be called to parse MP
>> tables which contains boot information.
>>
>> Fixes: 0f4a1e80989a ("x86/sev: Skip ROM range scans and validation for SEV-SNP guests")
>> Signed-off-by: Ajay Kaher <ajay.kaher@xxxxxxxxxxxx>
>> Signed-off-by: Ye Li <ye.li@xxxxxxxxxxxx>
>> Tested-by: Ye Li <ye.li@xxxxxxxxxxxx>
>
> That SOB chain is wrong. Ye's SOB means, he's sending the patch but that
> doesn't look like it.
>
>> ---
>> arch/x86/kernel/cpu/vmware.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
>> index 00189cd..3e2594d 100644
>> --- a/arch/x86/kernel/cpu/vmware.c
>> +++ b/arch/x86/kernel/cpu/vmware.c
>> @@ -26,6 +26,7 @@
>> #include <linux/export.h>
>> #include <linux/clocksource.h>
>> #include <linux/cpu.h>
>> +#include <linux/efi.h>
>> #include <linux/reboot.h>
>> #include <linux/static_call.h>
>> #include <asm/div64.h>
>> @@ -35,6 +36,8 @@
>> #include <asm/apic.h>
>> #include <asm/vmware.h>
>> #include <asm/svm.h>
>> +#include <asm/mem_encrypt.h>
>> +#include <asm/efi.h>
>>
>> #undef pr_fmt
>> #define pr_fmt(fmt) "vmware: " fmt
>> @@ -429,6 +432,10 @@ static void __init vmware_platform_setup(void)
>> pr_warn("Failed to get TSC freq from the hypervisor\n");
>> }
>>
>> + if (sev_status & MSR_AMD64_SEV_SNP_ENABLED &&
>
> cpu_feature_enabled(X86_FEATURE_SEV_SNP)

I think this should really be cc_platform_has(CC_ATTR_GUEST_SEV_SNP).

Thanks,
Tom

>
>> + !efi_enabled(EFI_BOOT))
>> + x86_init.mpparse.find_mptable = mpparse_find_mptable;
>> +
>> vmware_paravirt_ops_setup();
>>
>> #ifdef CONFIG_X86_IO_APIC
>> --
>