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Subject: [PATCH RFC v8 19/56] x86/fault: Return pfn from dump_pagetable() for SEV-specific fault handling.
Date:   Mon, 20 Feb 2023 12:38:10 -0600
Message-ID: <20230220183847.59159-20-michael.roth@amd.com>
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From: Ashish Kalra <ashish.kalra@amd.com>

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

Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
---
 arch/x86/mm/fault.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index afd4cde17001..f2b16dcfbd9a 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 */
-- 
2.25.1