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Message-Id: <20210928191009.32551-8-bp@alien8.de>
Date: Tue, 28 Sep 2021 21:10:08 +0200
From: Borislav Petkov <bp@...en8.de>
To: LKML <linux-kernel@...r.kernel.org>
Cc: Andi Kleen <ak@...ux.intel.com>, Andy Lutomirski <luto@...nel.org>,
Ard Biesheuvel <ardb@...nel.org>, Baoquan He <bhe@...hat.com>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Christian Borntraeger <borntraeger@...ibm.com>,
Daniel Vetter <daniel@...ll.ch>,
Dave Young <dyoung@...hat.com>,
David Airlie <airlied@...ux.ie>,
Heiko Carstens <hca@...ux.ibm.com>,
Joerg Roedel <joro@...tes.org>,
"Kirill A. Shutemov" <kirill@...temov.name>,
"Kuppuswamy, Sathyanarayanan"
<sathyanarayanan.kuppuswamy@...ux.intel.com>,
Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
Maxime Ripard <mripard@...nel.org>,
Michael Ellerman <mpe@...erman.id.au>,
Paul Mackerras <paulus@...ba.org>,
Tom Lendacky <thomas.lendacky@....com>,
Thomas Zimmermann <tzimmermann@...e.de>,
Vasily Gorbik <gor@...ux.ibm.com>,
VMware Graphics <linux-graphics-maintainer@...are.com>,
Will Deacon <will@...nel.org>,
Christoph Hellwig <hch@...radead.org>, x86@...nel.org,
linuxppc-dev@...ts.ozlabs.org, linux-s390@...r.kernel.org,
iommu@...ts.linux-foundation.org, kvm@...r.kernel.org,
linux-efi@...r.kernel.org, platform-driver-x86@...r.kernel.org,
amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
kexec@...ts.infradead.org
Subject: [PATCH 7/8] x86/sev: Replace occurrences of sev_es_active() with cc_platform_has()
From: Tom Lendacky <thomas.lendacky@....com>
Replace uses of sev_es_active() with the more generic cc_platform_has()
using CC_ATTR_GUEST_STATE_ENCRYPT. If future support is added for other
memory encyrption techonologies, the use of CC_ATTR_GUEST_STATE_ENCRYPT
can be updated, as required.
Signed-off-by: Tom Lendacky <thomas.lendacky@....com>
Signed-off-by: Borislav Petkov <bp@...e.de>
---
arch/x86/include/asm/mem_encrypt.h | 2 --
arch/x86/kernel/sev.c | 6 +++---
arch/x86/mm/mem_encrypt.c | 24 +++---------------------
arch/x86/realmode/init.c | 3 +--
4 files changed, 7 insertions(+), 28 deletions(-)
diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
index a5a58ccd1ee3..da14ede311aa 100644
--- a/arch/x86/include/asm/mem_encrypt.h
+++ b/arch/x86/include/asm/mem_encrypt.h
@@ -51,7 +51,6 @@ void __init mem_encrypt_free_decrypted_mem(void);
void __init mem_encrypt_init(void);
void __init sev_es_init_vc_handling(void);
-bool sev_es_active(void);
#define __bss_decrypted __section(".bss..decrypted")
@@ -74,7 +73,6 @@ static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }
static inline void __init sme_enable(struct boot_params *bp) { }
static inline void sev_es_init_vc_handling(void) { }
-static inline bool sev_es_active(void) { return false; }
static inline int __init
early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; }
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index a6895e440bc3..53a6837d354b 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -11,7 +11,7 @@
#include <linux/sched/debug.h> /* For show_regs() */
#include <linux/percpu-defs.h>
-#include <linux/mem_encrypt.h>
+#include <linux/cc_platform.h>
#include <linux/printk.h>
#include <linux/mm_types.h>
#include <linux/set_memory.h>
@@ -615,7 +615,7 @@ int __init sev_es_efi_map_ghcbs(pgd_t *pgd)
int cpu;
u64 pfn;
- if (!sev_es_active())
+ if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
return 0;
pflags = _PAGE_NX | _PAGE_RW;
@@ -774,7 +774,7 @@ void __init sev_es_init_vc_handling(void)
BUILD_BUG_ON(offsetof(struct sev_es_runtime_data, ghcb_page) % PAGE_SIZE);
- if (!sev_es_active())
+ if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
return;
if (!sev_es_check_cpu_features())
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 932007a6913b..2d04c39bea1d 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -361,25 +361,6 @@ int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size)
return early_set_memory_enc_dec(vaddr, size, true);
}
-/*
- * SME and SEV are very similar but they are not the same, so there are
- * times that the kernel will need to distinguish between SME and SEV. The
- * cc_platform_has() function is used for this. When a distinction isn't
- * needed, the CC_ATTR_MEM_ENCRYPT attribute can be used.
- *
- * The trampoline code is a good example for this requirement. Before
- * paging is activated, SME will access all memory as decrypted, but SEV
- * will access all memory as encrypted. So, when APs are being brought
- * up under SME the trampoline area cannot be encrypted, whereas under SEV
- * the trampoline area must be encrypted.
- */
-
-/* Needs to be called from non-instrumentable code */
-bool noinstr sev_es_active(void)
-{
- return sev_status & MSR_AMD64_SEV_ES_ENABLED;
-}
-
/* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
bool force_dma_unencrypted(struct device *dev)
{
@@ -449,7 +430,7 @@ static void print_mem_encrypt_feature_info(void)
pr_cont(" SEV");
/* Encrypted Register State */
- if (sev_es_active())
+ if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
pr_cont(" SEV-ES");
pr_cont("\n");
@@ -468,7 +449,8 @@ void __init mem_encrypt_init(void)
* With SEV, we need to unroll the rep string I/O instructions,
* but SEV-ES supports them through the #VC handler.
*/
- if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) && !sev_es_active())
+ if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) &&
+ !cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
static_branch_enable(&sev_enable_key);
print_mem_encrypt_feature_info();
diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index c878c5ee5a4c..4a3da7592b99 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -2,7 +2,6 @@
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/memblock.h>
-#include <linux/mem_encrypt.h>
#include <linux/cc_platform.h>
#include <linux/pgtable.h>
@@ -48,7 +47,7 @@ static void sme_sev_setup_real_mode(struct trampoline_header *th)
if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
th->flags |= TH_FLAGS_SME_ACTIVE;
- if (sev_es_active()) {
+ if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) {
/*
* Skip the call to verify_cpu() in secondary_startup_64 as it
* will cause #VC exceptions when the AP can't handle them yet.
--
2.29.2
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