1 files changed, 80 insertions, 45 deletions

diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 973756c89dac..17b3d003b2ea 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -657,32 +657,58 @@ static u64 __init get_jump_table_addr(void)
 	return ret;
 }
 
-static void pvalidate_pages(unsigned long vaddr, unsigned long npages, bool validate)
+static void pvalidate_pages(struct snp_psc_desc *desc)
 {
-	unsigned long vaddr_end;
+	struct psc_entry *e;
+	unsigned long vaddr;
+	unsigned int size;
+	unsigned int i;
+	bool validate;
 	int rc;
 
-	vaddr = vaddr & PAGE_MASK;
-	vaddr_end = vaddr + (npages << PAGE_SHIFT);
+	for (i = 0; i <= desc->hdr.end_entry; i++) {
+		e = &desc->entries[i];
+
+		vaddr = (unsigned long)pfn_to_kaddr(e->gfn);
+		size = e->pagesize ? RMP_PG_SIZE_2M : RMP_PG_SIZE_4K;
+		validate = e->operation == SNP_PAGE_STATE_PRIVATE;
+
+		rc = pvalidate(vaddr, size, validate);
+		if (rc == PVALIDATE_FAIL_SIZEMISMATCH && size == RMP_PG_SIZE_2M) {
+			unsigned long vaddr_end = vaddr + PMD_SIZE;
+
+			for (; vaddr < vaddr_end; vaddr += PAGE_SIZE) {
+				rc = pvalidate(vaddr, RMP_PG_SIZE_4K, validate);
+				if (rc)
+					break;
+			}
+		}
 
-	while (vaddr < vaddr_end) {
-		rc = pvalidate(vaddr, RMP_PG_SIZE_4K, validate);
 		if (WARN(rc, "Failed to validate address 0x%lx ret %d", vaddr, rc))
 			sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
-
-		vaddr = vaddr + PAGE_SIZE;
 	}
 }
 
-static void early_set_pages_state(unsigned long paddr, unsigned long npages, enum psc_op op)
+static void early_set_pages_state(unsigned long vaddr, unsigned long paddr,
+				  unsigned long npages, enum psc_op op)
 {
 	unsigned long paddr_end;
 	u64 val;
+	int ret;
+
+	vaddr = vaddr & PAGE_MASK;
 
 	paddr = paddr & PAGE_MASK;
 	paddr_end = paddr + (npages << PAGE_SHIFT);
 
 	while (paddr < paddr_end) {
+		if (op == SNP_PAGE_STATE_SHARED) {
+			/* Page validation must be rescinded before changing to shared */
+			ret = pvalidate(vaddr, RMP_PG_SIZE_4K, false);
+			if (WARN(ret, "Failed to validate address 0x%lx ret %d", paddr, ret))
+				goto e_term;
+		}
+
 		/*
 		 * Use the MSR protocol because this function can be called before
 		 * the GHCB is established.
@@ -703,7 +729,15 @@ static void early_set_pages_state(unsigned long paddr, unsigned long npages, enu
 			 paddr, GHCB_MSR_PSC_RESP_VAL(val)))
 			goto e_term;
 
-		paddr = paddr + PAGE_SIZE;
+		if (op == SNP_PAGE_STATE_PRIVATE) {
+			/* Page validation must be performed after changing to private */
+			ret = pvalidate(vaddr, RMP_PG_SIZE_4K, true);
+			if (WARN(ret, "Failed to validate address 0x%lx ret %d", paddr, ret))
+				goto e_term;
+		}
+
+		vaddr += PAGE_SIZE;
+		paddr += PAGE_SIZE;
 	}
 
 	return;
@@ -728,10 +762,7 @@ void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long padd
 	  * Ask the hypervisor to mark the memory pages as private in the RMP
 	  * table.
 	  */
-	early_set_pages_state(paddr, npages, SNP_PAGE_STATE_PRIVATE);
-
-	/* Validate the memory pages after they've been added in the RMP table. */
-	pvalidate_pages(vaddr, npages, true);
+	early_set_pages_state(vaddr, paddr, npages, SNP_PAGE_STATE_PRIVATE);
 }
 
 void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
@@ -746,11 +777,8 @@ void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr
 	if (!(sev_status & MSR_AMD64_SEV_SNP_ENABLED))
 		return;
 
-	/* Invalidate the memory pages before they are marked shared in the RMP table. */
-	pvalidate_pages(vaddr, npages, false);
-
 	 /* Ask hypervisor to mark the memory pages shared in the RMP table. */
-	early_set_pages_state(paddr, npages, SNP_PAGE_STATE_SHARED);
+	early_set_pages_state(vaddr, paddr, npages, SNP_PAGE_STATE_SHARED);
 }
 
 void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op)
@@ -834,10 +862,11 @@ out:
 	return ret;
 }
 
-static void __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
-			      unsigned long vaddr_end, int op)
+static unsigned long __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
+				       unsigned long vaddr_end, int op)
 {
 	struct ghcb_state state;
+	bool use_large_entry;
 	struct psc_hdr *hdr;
 	struct psc_entry *e;
 	unsigned long flags;
@@ -851,27 +880,37 @@ static void __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
 	memset(data, 0, sizeof(*data));
 	i = 0;
 
-	while (vaddr < vaddr_end) {
-		if (is_vmalloc_addr((void *)vaddr))
+	while (vaddr < vaddr_end && i < ARRAY_SIZE(data->entries)) {
+		hdr->end_entry = i;
+
+		if (is_vmalloc_addr((void *)vaddr)) {
 			pfn = vmalloc_to_pfn((void *)vaddr);
-		else
+			use_large_entry = false;
+		} else {
 			pfn = __pa(vaddr) >> PAGE_SHIFT;
+			use_large_entry = true;
+		}
 
 		e->gfn = pfn;
 		e->operation = op;
-		hdr->end_entry = i;
 
-		/*
-		 * Current SNP implementation doesn't keep track of the RMP page
-		 * size so use 4K for simplicity.
-		 */
-		e->pagesize = RMP_PG_SIZE_4K;
+		if (use_large_entry && IS_ALIGNED(vaddr, PMD_SIZE) &&
+		    (vaddr_end - vaddr) >= PMD_SIZE) {
+			e->pagesize = RMP_PG_SIZE_2M;
+			vaddr += PMD_SIZE;
+		} else {
+			e->pagesize = RMP_PG_SIZE_4K;
+			vaddr += PAGE_SIZE;
+		}
 
-		vaddr = vaddr + PAGE_SIZE;
 		e++;
 		i++;
 	}
 
+	/* Page validation must be rescinded before changing to shared */
+	if (op == SNP_PAGE_STATE_SHARED)
+		pvalidate_pages(data);
+
 	local_irq_save(flags);
 
 	if (sev_cfg.ghcbs_initialized)
@@ -879,6 +918,7 @@ static void __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
 	else
 		ghcb = boot_ghcb;
 
+	/* Invoke the hypervisor to perform the page state changes */
 	if (!ghcb || vmgexit_psc(ghcb, data))
 		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
 
@@ -886,29 +926,28 @@ static void __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
 		__sev_put_ghcb(&state);
 
 	local_irq_restore(flags);
+
+	/* Page validation must be performed after changing to private */
+	if (op == SNP_PAGE_STATE_PRIVATE)
+		pvalidate_pages(data);
+
+	return vaddr;
 }
 
 static void set_pages_state(unsigned long vaddr, unsigned long npages, int op)
 {
-	unsigned long vaddr_end, next_vaddr;
 	struct snp_psc_desc desc;
+	unsigned long vaddr_end;
 
 	/* Use the MSR protocol when a GHCB is not available. */
 	if (!boot_ghcb)
-		return early_set_pages_state(__pa(vaddr), npages, op);
+		return early_set_pages_state(vaddr, __pa(vaddr), npages, op);
 
 	vaddr = vaddr & PAGE_MASK;
 	vaddr_end = vaddr + (npages << PAGE_SHIFT);
 
-	while (vaddr < vaddr_end) {
-		/* Calculate the last vaddr that fits in one struct snp_psc_desc. */
-		next_vaddr = min_t(unsigned long, vaddr_end,
-				   (VMGEXIT_PSC_MAX_ENTRY * PAGE_SIZE) + vaddr);
-
-		__set_pages_state(&desc, vaddr, next_vaddr, op);
-
-		vaddr = next_vaddr;
-	}
+	while (vaddr < vaddr_end)
+		vaddr = __set_pages_state(&desc, vaddr, vaddr_end, op);
 }
 
 void snp_set_memory_shared(unsigned long vaddr, unsigned long npages)
@@ -916,8 +955,6 @@ void snp_set_memory_shared(unsigned long vaddr, unsigned long npages)
 	if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
 		return;
 
-	pvalidate_pages(vaddr, npages, false);
-
 	set_pages_state(vaddr, npages, SNP_PAGE_STATE_SHARED);
 }
 
@@ -927,8 +964,6 @@ void snp_set_memory_private(unsigned long vaddr, unsigned long npages)
 		return;
 
 	set_pages_state(vaddr, npages, SNP_PAGE_STATE_PRIVATE);
-
-	pvalidate_pages(vaddr, npages, true);
 }
 
 static int snp_set_vmsa(void *va, bool vmsa)