diff mbox series

[06/11] x86/sev: Replace occurrences of sev_es_active() with prot_guest_has()

Message ID ba565128b88661a656fc3972f01bb2e295158a15.1627424774.git.thomas.lendacky@amd.com (mailing list archive)
State New
Headers show
Series Implement generic prot_guest_has() helper function | expand

Commit Message

Tom Lendacky July 27, 2021, 10:26 p.m. UTC
Replace occurrences of sev_es_active() with the more generic
prot_guest_has() using PATTR_GUEST_PROT_STATE, except for in
arch/x86/kernel/sev*.c and arch/x86/mm/mem_encrypt*.c where PATTR_SEV_ES
will be used. If future support is added for other memory encyrption
techonologies, the use of PATTR_GUEST_PROT_STATE can be updated, as
required, to specifically use PATTR_SEV_ES.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 arch/x86/include/asm/mem_encrypt.h | 2 --
 arch/x86/kernel/sev.c              | 6 +++---
 arch/x86/mm/mem_encrypt.c          | 7 +++----
 arch/x86/realmode/init.c           | 3 +--
 4 files changed, 7 insertions(+), 11 deletions(-)

Comments

Joerg Roedel Aug. 2, 2021, 10:45 a.m. UTC | #1
On Tue, Jul 27, 2021 at 05:26:09PM -0500, Tom Lendacky wrote:
> @@ -48,7 +47,7 @@ static void sme_sev_setup_real_mode(struct trampoline_header *th)
>  	if (prot_guest_has(PATTR_HOST_MEM_ENCRYPT))
>  		th->flags |= TH_FLAGS_SME_ACTIVE;
>  
> -	if (sev_es_active()) {
> +	if (prot_guest_has(PATTR_GUEST_PROT_STATE)) {
>  		/*
>  		 * Skip the call to verify_cpu() in secondary_startup_64 as it
>  		 * will cause #VC exceptions when the AP can't handle them yet.

Not sure how TDX will handle AP booting, are you sure it needs this
special setup as well? Otherwise a check for SEV-ES would be better
instead of the generic PATTR_GUEST_PROT_STATE.

Regards,

Joerg
Tom Lendacky Aug. 9, 2021, 9:59 p.m. UTC | #2
On 8/2/21 5:45 AM, Joerg Roedel wrote:
> On Tue, Jul 27, 2021 at 05:26:09PM -0500, Tom Lendacky wrote:
>> @@ -48,7 +47,7 @@ static void sme_sev_setup_real_mode(struct trampoline_header *th)
>>  	if (prot_guest_has(PATTR_HOST_MEM_ENCRYPT))
>>  		th->flags |= TH_FLAGS_SME_ACTIVE;
>>  
>> -	if (sev_es_active()) {
>> +	if (prot_guest_has(PATTR_GUEST_PROT_STATE)) {
>>  		/*
>>  		 * Skip the call to verify_cpu() in secondary_startup_64 as it
>>  		 * will cause #VC exceptions when the AP can't handle them yet.
> 
> Not sure how TDX will handle AP booting, are you sure it needs this
> special setup as well? Otherwise a check for SEV-ES would be better
> instead of the generic PATTR_GUEST_PROT_STATE.

Yes, I'm not sure either. I figure that change can be made, if needed, as
part of the TDX support.

Thanks,
Tom

> 
> Regards,
> 
> Joerg
>
Kuppuswamy, Sathyanarayanan Aug. 9, 2021, 10:08 p.m. UTC | #3
On 8/9/21 2:59 PM, Tom Lendacky wrote:
>> Not sure how TDX will handle AP booting, are you sure it needs this
>> special setup as well? Otherwise a check for SEV-ES would be better
>> instead of the generic PATTR_GUEST_PROT_STATE.
> Yes, I'm not sure either. I figure that change can be made, if needed, as
> part of the TDX support.

We don't plan to set PROT_STATE. So it does not affect TDX.
For SMP, we use MADT ACPI table for AP booting.
diff mbox series

Patch

diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
index 7e25de37c148..797146e0cd6b 100644
--- a/arch/x86/include/asm/mem_encrypt.h
+++ b/arch/x86/include/asm/mem_encrypt.h
@@ -50,7 +50,6 @@  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);
 bool amd_prot_guest_has(unsigned int attr);
 
 #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 bool amd_prot_guest_has(unsigned int attr) { return false; }
 
 static inline int __init
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index a6895e440bc3..66a4ab9d95d7 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/protected_guest.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 (!prot_guest_has(PATTR_SEV_ES))
 		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 (!prot_guest_has(PATTR_SEV_ES))
 		return;
 
 	if (!sev_es_check_cpu_features())
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index eb5cae93b238..451de8e84fce 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -383,8 +383,7 @@  static bool sme_active(void)
 	return sme_me_mask && !sev_active();
 }
 
-/* Needs to be called from non-instrumentable code */
-bool noinstr sev_es_active(void)
+static bool sev_es_active(void)
 {
 	return sev_status & MSR_AMD64_SEV_ES_ENABLED;
 }
@@ -482,7 +481,7 @@  static void print_mem_encrypt_feature_info(void)
 		pr_cont(" SEV");
 
 	/* Encrypted Register State */
-	if (sev_es_active())
+	if (amd_prot_guest_has(PATTR_SEV_ES))
 		pr_cont(" SEV-ES");
 
 	pr_cont("\n");
@@ -501,7 +500,7 @@  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 (amd_prot_guest_has(PATTR_SEV) && !sev_es_active())
+	if (amd_prot_guest_has(PATTR_SEV) && !amd_prot_guest_has(PATTR_SEV_ES))
 		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 2109ae569c67..7711d0071f41 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/protected_guest.h>
 #include <linux/pgtable.h>
 
@@ -48,7 +47,7 @@  static void sme_sev_setup_real_mode(struct trampoline_header *th)
 	if (prot_guest_has(PATTR_HOST_MEM_ENCRYPT))
 		th->flags |= TH_FLAGS_SME_ACTIVE;
 
-	if (sev_es_active()) {
+	if (prot_guest_has(PATTR_GUEST_PROT_STATE)) {
 		/*
 		 * Skip the call to verify_cpu() in secondary_startup_64 as it
 		 * will cause #VC exceptions when the AP can't handle them yet.