[RFC,v7,22/64] x86/fault: Return pfn from dump_pagetable() for SEV-specific fault handling.

Commit Message

Michael Roth Dec. 14, 2022, 7:40 p.m. UTC

From: Ashish Kalra <[e-mail]>

Return pfn from dump_pagetable() to do SEV-specific
fault handling. Used for handling SNP RMP page fault.

Signed-off-by: Ashish Kalra <[e-mail]>
Signed-off-by: Michael Roth <[e-mail]>
---
 arch/x86/mm/fault.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

Patch

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index d611051dcf1e..ded53879f98d 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -311,7 +311,7 @@  static bool low_pfn(unsigned long pfn)
 	return pfn < max_low_pfn;
 }
 
-static void dump_pagetable(unsigned long address)
+static unsigned long dump_pagetable(unsigned long address)
 {
 	pgd_t *base = __va(read_cr3_pa());
 	pgd_t *pgd = &base[pgd_index(address)];
@@ -345,8 +345,10 @@  static void dump_pagetable(unsigned long address)
 
 	pte = pte_offset_kernel(pmd, address);
 	pr_cont("*pte = %0*Lx ", sizeof(*pte) * 2, (u64)pte_val(*pte));
+	return 0;
 out:
 	pr_cont("\n");
+	return 0;
 }
 
 #else /* CONFIG_X86_64: */
@@ -367,10 +369,11 @@  static int bad_address(void *p)
 	return get_kernel_nofault(dummy, (unsigned long *)p);
 }
 
-static void dump_pagetable(unsigned long address)
+static unsigned long dump_pagetable(unsigned long address)
 {
 	pgd_t *base = __va(read_cr3_pa());
 	pgd_t *pgd = base + pgd_index(address);
+	unsigned long pfn;
 	p4d_t *p4d;
 	pud_t *pud;
 	pmd_t *pmd;
@@ -388,6 +391,7 @@  static void dump_pagetable(unsigned long address)
 	if (bad_address(p4d))
 		goto bad;
 
+	pfn = p4d_pfn(*p4d);
 	pr_cont("P4D %lx ", p4d_val(*p4d));
 	if (!p4d_present(*p4d) || p4d_large(*p4d))
 		goto out;
@@ -396,6 +400,7 @@  static void dump_pagetable(unsigned long address)
 	if (bad_address(pud))
 		goto bad;
 
+	pfn = pud_pfn(*pud);
 	pr_cont("PUD %lx ", pud_val(*pud));
 	if (!pud_present(*pud) || pud_large(*pud))
 		goto out;
@@ -404,6 +409,7 @@  static void dump_pagetable(unsigned long address)
 	if (bad_address(pmd))
 		goto bad;
 
+	pfn = pmd_pfn(*pmd);
 	pr_cont("PMD %lx ", pmd_val(*pmd));
 	if (!pmd_present(*pmd) || pmd_large(*pmd))
 		goto out;
@@ -412,13 +418,14 @@  static void dump_pagetable(unsigned long address)
 	if (bad_address(pte))
 		goto bad;
 
+	pfn = pte_pfn(*pte);
 	pr_cont("PTE %lx", pte_val(*pte));
 out:
 	pr_cont("\n");
-
-	return;
+	return pfn;
 bad:
 	pr_info("BAD\n");
+	return -1;
 }
 
 #endif /* CONFIG_X86_64 */