x86/hyperv: Remove hv_isolation_type_en_snp

In ms_hyperv_init_platform(), do not distinguish between a SNP VM with the paravisor and a SNP VM without the paravisor. Replace hv_isolation_type_en_snp() with !hyperv_paravisor_present && hv_isolation_type_snp(). The hv_isolation_type_en_snp() in drivers/hv/hv.c and drivers/hv/hv_common.c can be changed to hv_isolation_type_snp() since we know !hyperv_paravisor_present is true there. Signed-off-by: Dexuan Cui <decui@microsoft.com>
dcui · Aug 12, 2023 · 323de39 · 323de39
1 parent 81e938e
commit 323de39
Show file tree

Hide file tree

Showing 7 changed files with 12 additions and 33 deletions.
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
@@ -52,7 +52,7 @@ static int hyperv_init_ghcb(void)
 	void *ghcb_va;
 	void **ghcb_base;
 
-	if (!hv_isolation_type_snp())
+	if (!hyperv_paravisor_present || !hv_isolation_type_snp())
 		return 0;
 
 	if (!hv_ghcb_pg)
@@ -117,7 +117,7 @@ static int hv_cpu_init(unsigned int cpu)
 			 * is blocked to run in Confidential VM. So only decrypt assist
 			 * page in non-root partition here.
 			 */
-			if (*hvp && hv_isolation_type_en_snp()) {
+			if (*hvp && !hyperv_paravisor_present && hv_isolation_type_snp()) {
 				WARN_ON_ONCE(set_memory_decrypted((unsigned long)(*hvp), 1));
 				memset(*hvp, 0, PAGE_SIZE);
 			}
@@ -465,7 +465,7 @@ void __init hyperv_init(void)
 			goto common_free;
 	}
 
-	if (hv_isolation_type_snp()) {
+	if (hyperv_paravisor_present && hv_isolation_type_snp()) {
 		/* Negotiate GHCB Version. */
 		if (!hv_ghcb_negotiate_protocol())
 			hv_ghcb_terminate(SEV_TERM_SET_GEN,
@@ -588,7 +588,7 @@ void __init hyperv_init(void)
 	hv_query_ext_cap(0);
 
 	/* Find the VTL */
-	if (hv_isolation_type_en_snp())
+	if (!hyperv_paravisor_present && hv_isolation_type_snp())
 		ms_hyperv.vtl = get_vtl();
 
 	return;

diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
@@ -624,24 +624,14 @@ bool hv_is_isolation_supported(void)
 DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
 
 /*
- * hv_isolation_type_snp - Check system runs in the AMD SEV-SNP based
+ * hv_isolation_type_snp - Check if the system runs in an AMD SEV-SNP based
  * isolation VM.
  */
 bool hv_isolation_type_snp(void)
 {
 	return static_branch_unlikely(&isolation_type_snp);
 }
 
-DEFINE_STATIC_KEY_FALSE(isolation_type_en_snp);
-/*
- * hv_isolation_type_en_snp - Check system runs in the AMD SEV-SNP based
- * isolation enlightened VM.
- */
-bool hv_isolation_type_en_snp(void)
-{
-	return static_branch_unlikely(&isolation_type_en_snp);
-}
-
 DEFINE_STATIC_KEY_FALSE(isolation_type_tdx);
 /*
  * hv_isolation_type_tdx - Check if the system runs in an Intel TDX based

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
@@ -26,7 +26,6 @@
 union hv_ghcb;
 
 DECLARE_STATIC_KEY_FALSE(isolation_type_snp);
-DECLARE_STATIC_KEY_FALSE(isolation_type_en_snp);
 DECLARE_STATIC_KEY_FALSE(isolation_type_tdx);
 
 typedef int (*hyperv_fill_flush_list_func)(
@@ -269,8 +268,7 @@ static inline void hv_vtom_init(void) {}
 static int hv_snp_boot_ap(int cpu, unsigned long start_ip) { return 0; }
 #endif
 
-extern bool hv_isolation_type_snp(void);
-extern bool hv_isolation_type_en_snp(void);
+bool hv_isolation_type_snp(void);
 
 static inline bool hv_is_synic_reg(unsigned int reg)
 {

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
@@ -306,7 +306,7 @@ static void __init hv_smp_prepare_cpus(unsigned int max_cpus)
 	 *  Override wakeup_secondary_cpu_64 callback for SEV-SNP
 	 *  enlightened guest.
 	 */
-	if (hv_isolation_type_en_snp())
+	if (!hyperv_paravisor_present && hv_isolation_type_snp())
 		apic->wakeup_secondary_cpu_64 = hv_snp_boot_ap;
 
 	if (!hv_root_partition)
@@ -442,9 +442,7 @@ static void __init ms_hyperv_init_platform(void)
 			ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
 
 
-		if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) {
-			static_branch_enable(&isolation_type_en_snp);
-		} else if (hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP) {
+		if (hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP) {
 			static_branch_enable(&isolation_type_snp);
 		} else if (hv_get_isolation_type() == HV_ISOLATION_TYPE_TDX) {
 			static_branch_enable(&isolation_type_tdx);

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
@@ -166,7 +166,7 @@ int hv_synic_alloc(void)
 		}
 
 		if (!hyperv_paravisor_present &&
-		    (hv_isolation_type_en_snp() || hv_isolation_type_tdx())) {
+		    (hv_isolation_type_snp() || hv_isolation_type_tdx())) {
 			ret = set_memory_decrypted((unsigned long)
 				hv_cpu->synic_message_page, 1);
 			if (ret) {
@@ -227,7 +227,7 @@ void hv_synic_free(void)
 		}
 
 		if (!hyperv_paravisor_present &&
-		    (hv_isolation_type_en_snp() || hv_isolation_type_tdx())) {
+		    (hv_isolation_type_snp() || hv_isolation_type_tdx())) {
 			if (hv_cpu->synic_message_page) {
 				ret = set_memory_encrypted((unsigned long)
 					hv_cpu->synic_message_page, 1);

diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
@@ -386,7 +386,7 @@ int hv_common_cpu_init(unsigned int cpu)
 		}
 
 		if (!hyperv_paravisor_present &&
-		    (hv_isolation_type_en_snp() || hv_isolation_type_tdx())) {
+		    (hv_isolation_type_snp() || hv_isolation_type_tdx())) {
 			ret = set_memory_decrypted((unsigned long)mem, pgcount);
 			if (ret) {
 				/* It may be unsafe to free 'mem' */
@@ -535,12 +535,6 @@ bool __weak hv_isolation_type_snp(void)
 }
 EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
 
-bool __weak hv_isolation_type_en_snp(void)
-{
-	return false;
-}
-EXPORT_SYMBOL_GPL(hv_isolation_type_en_snp);
-
 bool __weak hv_isolation_type_tdx(void)
 {
 	return false;

diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
@@ -64,8 +64,7 @@ extern void * __percpu *hyperv_pcpu_output_arg;
 
 extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
-extern bool hv_isolation_type_snp(void);
-extern bool hv_isolation_type_en_snp(void);
+bool hv_isolation_type_snp(void);
 bool hv_isolation_type_tdx(void);
 
 /* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */