Commit 007c74e1 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'stable/for-linus-5.11' of... 

Merge branch 'stable/for-linus-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb

Pull swiotlb update from Konrad Rzeszutek Wilk:
 "A generic (but for right now engaged only with AMD SEV) mechanism to
  adjust a larger size SWIOTLB based on the total memory of the SEV
  guests which right now require the bounce buffer for interacting with
  the outside world.

  Normal knobs (swiotlb=XYZ) still work"

* 'stable/for-linus-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  x86,swiotlb: Adjust SWIOTLB bounce buffer size for SEV guests
parents 009bd55d e998879d

arch/x86/include/asm/mem_encrypt.h

+2 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ void __init sme_map_bootdata(char *real_mode_data); 
void __init sme_unmap_bootdata(char *real_mode_data);



void __init sme_early_init(void);

void __init sev_setup_arch(void);



void __init sme_encrypt_kernel(struct boot_params *bp);

void __init sme_enable(struct boot_params *bp);
@@ -69,6 +70,7 @@ static inline void __init sme_map_bootdata(char *real_mode_data) { } 
static inline void __init sme_unmap_bootdata(char *real_mode_data) { }



static inline void __init sme_early_init(void) { }

static inline void __init sev_setup_arch(void) { }



static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }

static inline void __init sme_enable(struct boot_params *bp) { }

arch/x86/kernel/setup.c

+6 −0
Original line number Diff line number Diff line
@@ -1049,6 +1049,12 @@ void __init setup_arch(char **cmdline_p) 
	memblock_set_current_limit(ISA_END_ADDRESS);

	e820__memblock_setup();



	/*

	 * Needs to run after memblock setup because it needs the physical

	 * memory size.

	 */

	sev_setup_arch();



	reserve_bios_regions();



	efi_fake_memmap();

arch/x86/mm/mem_encrypt.c

+31 −0
Original line number Diff line number Diff line
@@ -198,6 +198,37 @@ void __init sme_early_init(void) 
		swiotlb_force = SWIOTLB_FORCE;

}



void __init sev_setup_arch(void)

{

	phys_addr_t total_mem = memblock_phys_mem_size();

	unsigned long size;



	if (!sev_active())

		return;



	/*

	 * For SEV, all DMA has to occur via shared/unencrypted pages.

	 * SEV uses SWIOTLB to make this happen without changing device

	 * drivers. However, depending on the workload being run, the

	 * default 64MB of SWIOTLB may not be enough and SWIOTLB may

	 * run out of buffers for DMA, resulting in I/O errors and/or

	 * performance degradation especially with high I/O workloads.

	 *

	 * Adjust the default size of SWIOTLB for SEV guests using

	 * a percentage of guest memory for SWIOTLB buffers.

	 * Also, as the SWIOTLB bounce buffer memory is allocated

	 * from low memory, ensure that the adjusted size is within

	 * the limits of low available memory.

	 *

	 * The percentage of guest memory used here for SWIOTLB buffers

	 * is more of an approximation of the static adjustment which

	 * 64MB for <1G, and ~128M to 256M for 1G-to-4G, i.e., the 6%

	 */

	size = total_mem * 6 / 100;

	size = clamp_val(size, IO_TLB_DEFAULT_SIZE, SZ_1G);

	swiotlb_adjust_size(size);

}



static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)

{

	pgprot_t old_prot, new_prot;

include/linux/swiotlb.h

+8 −0
Original line number Diff line number Diff line
@@ -30,6 +30,9 @@ enum swiotlb_force { 
 */

#define IO_TLB_SHIFT 11



/* default to 64MB */

#define IO_TLB_DEFAULT_SIZE (64UL<<20)



extern void swiotlb_init(int verbose);

int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose);

extern unsigned long swiotlb_nr_tbl(void);
@@ -78,6 +81,7 @@ void __init swiotlb_exit(void); 
unsigned int swiotlb_max_segment(void);

size_t swiotlb_max_mapping_size(struct device *dev);

bool is_swiotlb_active(void);

void __init swiotlb_adjust_size(unsigned long new_size);

#else

#define swiotlb_force SWIOTLB_NO_FORCE

static inline bool is_swiotlb_buffer(phys_addr_t paddr)
@@ -100,6 +104,10 @@ static inline bool is_swiotlb_active(void) 
{

	return false;

}



static inline void swiotlb_adjust_size(unsigned long new_size)

{

}

#endif /* CONFIG_SWIOTLB */



extern void swiotlb_print_info(void);

kernel/dma/swiotlb.c

+18 −2
Original line number Diff line number Diff line
@@ -152,8 +152,6 @@ void swiotlb_set_max_segment(unsigned int val) 
		max_segment = rounddown(val, PAGE_SIZE);

}



/* default to 64MB */

#define IO_TLB_DEFAULT_SIZE (64UL<<20)

unsigned long swiotlb_size_or_default(void)

{

	unsigned long size;
@@ -163,6 +161,24 @@ unsigned long swiotlb_size_or_default(void) 
	return size ? size : (IO_TLB_DEFAULT_SIZE);

}



void __init swiotlb_adjust_size(unsigned long new_size)

{

	unsigned long size;



	/*

	 * If swiotlb parameter has not been specified, give a chance to

	 * architectures such as those supporting memory encryption to

	 * adjust/expand SWIOTLB size for their use.

	 */

	if (!io_tlb_nslabs) {

		size = ALIGN(new_size, 1 << IO_TLB_SHIFT);

		io_tlb_nslabs = size >> IO_TLB_SHIFT;

		io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);



		pr_info("SWIOTLB bounce buffer size adjusted to %luMB", size >> 20);

	}

}



void swiotlb_print_info(void)

{

	unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT;

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