Commit e4c00c4c authored by Ashish Kalra's avatar Ashish Kalra Committed by Borislav Petkov (AMD)
Browse files

x86/sev: Add new dump_rmp parameter to snp_leak_pages() API 



When leaking certain page types, such as Hypervisor Fixed (HV_FIXED)
pages, it does not make sense to dump RMP contents for the 2MB range of
the page(s) being leaked. In the case of HV_FIXED pages, this is not an
error situation where the surrounding 2MB page RMP entries can provide
debug information.

Add new __snp_leak_pages() API with dump_rmp bool parameter to support
continue adding pages to the snp_leaked_pages_list but not issue
dump_rmpentry().

Make snp_leak_pages() a wrapper for the common case which also allows
existing users to continue to dump RMP entries.

Suggested-by: default avatarThomas Lendacky <Thomas.Lendacky@amd.com>
Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarAshish Kalra <ashish.kalra@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Acked-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/cover.1758057691.git.ashish.kalra@amd.com
parent 85df1cd1

arch/x86/include/asm/sev.h

+6 −1
Original line number Diff line number Diff line
@@ -655,9 +655,13 @@ void snp_dump_hva_rmpentry(unsigned long address); 
int psmash(u64 pfn);

int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, u32 asid, bool immutable);

int rmp_make_shared(u64 pfn, enum pg_level level);

void snp_leak_pages(u64 pfn, unsigned int npages);

void __snp_leak_pages(u64 pfn, unsigned int npages, bool dump_rmp);

void kdump_sev_callback(void);

void snp_fixup_e820_tables(void);

static inline void snp_leak_pages(u64 pfn, unsigned int pages)

{

	__snp_leak_pages(pfn, pages, true);

}

#else

static inline bool snp_probe_rmptable_info(void) { return false; }

static inline int snp_rmptable_init(void) { return -ENOSYS; }
@@ -670,6 +674,7 @@ static inline int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, u32 as 
	return -ENODEV;

}

static inline int rmp_make_shared(u64 pfn, enum pg_level level) { return -ENODEV; }

static inline void __snp_leak_pages(u64 pfn, unsigned int npages, bool dump_rmp) {}

static inline void snp_leak_pages(u64 pfn, unsigned int npages) {}

static inline void kdump_sev_callback(void) { }

static inline void snp_fixup_e820_tables(void) {}

arch/x86/virt/svm/sev.c

+4 −3
Original line number Diff line number Diff line
@@ -1029,7 +1029,7 @@ int rmp_make_shared(u64 pfn, enum pg_level level) 
}

EXPORT_SYMBOL_GPL(rmp_make_shared);



void snp_leak_pages(u64 pfn, unsigned int npages)

void __snp_leak_pages(u64 pfn, unsigned int npages, bool dump_rmp)

{

	struct page *page = pfn_to_page(pfn);
@@ -1052,6 +1052,7 @@ void snp_leak_pages(u64 pfn, unsigned int npages) 
		    (PageHead(page) && compound_nr(page) <= npages))

			list_add_tail(&page->buddy_list, &snp_leaked_pages_list);



		if (dump_rmp)

			dump_rmpentry(pfn);

		snp_nr_leaked_pages++;

		pfn++;
@@ -1059,7 +1060,7 @@ void snp_leak_pages(u64 pfn, unsigned int npages) 
	}

	spin_unlock(&snp_leaked_pages_list_lock);

}

EXPORT_SYMBOL_GPL(snp_leak_pages);

EXPORT_SYMBOL_GPL(__snp_leak_pages);



void kdump_sev_callback(void)

{