Commit 655a0fa3 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Borislav Petkov
Browse files

x86/coco: Explicitly declare type of confidential computing platform 



The kernel derives the confidential computing platform
type it is running as from sme_me_mask on AMD or by using
hv_is_isolation_supported() on HyperV isolation VMs. This detection
process will be more complicated as more platforms get added.

Declare a confidential computing vendor variable explicitly and set it
via cc_set_vendor() on the respective platform.

  [ bp: Massage commit message, fixup HyperV check. ]

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20220222185740.26228-4-kirill.shutemov@linux.intel.com
parent 61983110

arch/x86/coco/core.c

+17 −12
Original line number Diff line number Diff line
@@ -9,18 +9,15 @@ 


#include <linux/export.h>

#include <linux/cc_platform.h>

#include <linux/mem_encrypt.h>



#include <asm/mshyperv.h>

#include <asm/coco.h>

#include <asm/processor.h>



static bool __maybe_unused intel_cc_platform_has(enum cc_attr attr)

static enum cc_vendor vendor __ro_after_init;



static bool intel_cc_platform_has(enum cc_attr attr)

{

#ifdef CONFIG_INTEL_TDX_GUEST

	return false;

#else

	return false;

#endif

}



/*
@@ -74,12 +71,20 @@ static bool hyperv_cc_platform_has(enum cc_attr attr) 


bool cc_platform_has(enum cc_attr attr)

{

	if (sme_me_mask)

	switch (vendor) {

	case CC_VENDOR_AMD:

		return amd_cc_platform_has(attr);



	if (hv_is_isolation_supported())

	case CC_VENDOR_INTEL:

		return intel_cc_platform_has(attr);

	case CC_VENDOR_HYPERV:

		return hyperv_cc_platform_has(attr);



	default:

		return false;

	}

}

EXPORT_SYMBOL_GPL(cc_platform_has);



__init void cc_set_vendor(enum cc_vendor v)

{

	vendor = v;

}

arch/x86/include/asm/coco.h

0 → 100644
+14 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _ASM_X86_COCO_H

#define _ASM_X86_COCO_H



enum cc_vendor {

	CC_VENDOR_NONE,

	CC_VENDOR_AMD,

	CC_VENDOR_HYPERV,

	CC_VENDOR_INTEL,

};



void cc_set_vendor(enum cc_vendor v);



#endif /* _ASM_X86_COCO_H */

arch/x86/kernel/cpu/mshyperv.c

+6 −0
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <asm/nmi.h>

#include <clocksource/hyperv_timer.h>

#include <asm/numa.h>

#include <asm/coco.h>



/* Is Linux running as the root partition? */

bool hv_root_partition;
@@ -344,6 +345,11 @@ static void __init ms_hyperv_init_platform(void) 
		 */

		swiotlb_force = SWIOTLB_FORCE;

#endif

		/* Isolation VMs are unenlightened SEV-based VMs, thus this check: */

		if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {

			if (hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE)

				cc_set_vendor(CC_VENDOR_HYPERV);

		}

	}



	if (hv_max_functions_eax >= HYPERV_CPUID_NESTED_FEATURES) {

arch/x86/mm/mem_encrypt_identity.c

+7 −4
Original line number Diff line number Diff line
@@ -44,6 +44,7 @@ 
#include <asm/setup.h>

#include <asm/sections.h>

#include <asm/cmdline.h>

#include <asm/coco.h>



#include "mm_internal.h"
@@ -565,8 +566,7 @@ void __init sme_enable(struct boot_params *bp) 
	} else {

		/* SEV state cannot be controlled by a command line option */

		sme_me_mask = me_mask;

		physical_mask &= ~sme_me_mask;

		return;

		goto out;

	}



	/*
@@ -600,6 +600,9 @@ void __init sme_enable(struct boot_params *bp) 
		sme_me_mask = 0;

	else

		sme_me_mask = active_by_default ? me_mask : 0;



out:

	if (sme_me_mask) {

		physical_mask &= ~sme_me_mask;

		cc_set_vendor(CC_VENDOR_AMD);

	}

}