[PATCH 0/2][RFC] Introduce "efi_fake_mem_mirror" boot option

[PATCH 0/2][RFC] Introduce "efi_fake_mem_mirror" boot option

[Taku Izumi]

UEFI spec 2.5 introduces new Memory Attribute Definition named
EFI_MEMORY_MORE_RELIABLE which indicates which memory ranges are
mirrored. Now linux kernel can recognize which memory ranges are mirrored
by handling EFI_MEMORY_MORE_RELIABLE attributes.
However testing this feature necesitates boxes with UEFI spec 2.5 complied
firmware. 

This patchset introduces new boot option named "efi_fake_mem_mirror".
By specifying this parameter, you can mark specific memory as
mirrored memory. This is useful for debugging of Memory Address Range
Mirroring feature.

Taku Izumi (2):
  efi: Add EFI_MEMORY_MORE_RELIABLE support to efi_md_typeattr_format()
  x86, efi: Add "efi_fake_mem_mirror" boot option

 Documentation/kernel-parameters.txt |   8 ++
 arch/x86/include/asm/efi.h          |   2 +
 arch/x86/kernel/setup.c             |   4 +-
 arch/x86/platform/efi/efi.c         |   2 +-
 arch/x86/platform/efi/quirks.c      | 169 ++++++++++++++++++++++++++++++++++++
 drivers/firmware/efi/efi.c          |   6 +-
 6 files changed, 187 insertions(+), 4 deletions(-)

-- 
1.8.3.1

[PATCH 1/2] efi: Add EFI_MEMORY_MORE_RELIABLE support to efi_md_typeattr_format()

[Taku Izumi]

UEFI spec 2.5 introduces new Memory Attribute Definition named
EFI_MEMORY_MORE_RELIABLE. This patch adds this new attribute
support to efi_md_typeattr_format().

Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
---
 drivers/firmware/efi/efi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index d6144e3..aadc1c4 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -589,12 +589,14 @@ char * __init efi_md_typeattr_format(char *buf, size_t size,
 	attr = md->attribute;
 	if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
 		     EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP |
-		     EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME))
+		     EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME |
+		     EFI_MEMORY_MORE_RELIABLE))
 		snprintf(pos, size, "|attr=0x%016llx]",
 			 (unsigned long long)attr);
 	else
-		snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
+		snprintf(pos, size, "|%3s|%4s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
 			 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
+			 attr & EFI_MEMORY_MORE_RELIABLE ? "RELY" : "",
 			 attr & EFI_MEMORY_XP      ? "XP"  : "",
 			 attr & EFI_MEMORY_RP      ? "RP"  : "",
 			 attr & EFI_MEMORY_WP      ? "WP"  : "",
-- 
1.8.3.1

[PATCH 2/2] x86, efi: Add "efi_fake_mem_mirror" boot option

[Taku Izumi]

This patch introduces new boot option named "efi_fake_mem_mirror".
By specifying this parameter, you can mark specific memory as
mirrored memory. This is useful for debugging of Address Range
Mirroring feature.

For example, if you specify "efi_fake_mem_mirror=2G@4G,2G@0x10a0000000",
the original (firmware provided) EFI memmap will be updated so that
the specified memory regions have EFI_MEMORY_MORE_RELIABLE attribute:

 <original EFI memmap>
   efi: mem00: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000000000-0x0000000000001000) (0MB)
   efi: mem01: [Loader Data        |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000001000-0x0000000000002000) (0MB)
   ...
   efi: mem35: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000047ee6000-0x0000000048014000) (1MB)
   efi: mem36: [Conventional Memory|   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x00000020a0000000) (129536MB)
   efi: mem37: [Reserved           |RUN|    |  |  |  |   |  |  |  |UC] range=[0x0000000060000000-0x0000000090000000) (768MB)

 <updated EFI memmap>
   efi: mem00: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000000000-0x0000000000001000) (0MB)
   efi: mem01: [Loader Data        |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000001000-0x0000000000002000) (0MB)
   ...
   efi: mem35: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000047ee6000-0x0000000048014000) (1MB)
   efi: mem36: [Conventional Memory|   |RELY|  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x0000000180000000) (2048MB)
   efi: mem37: [Conventional Memory|   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000180000000-0x00000010a0000000) (61952MB)
   efi: mem38: [Conventional Memory|   |RELY|  |  |  |   |WB|WT|WC|UC] range=[0x00000010a0000000-0x0000001120000000) (2048MB)
   efi: mem39: [Conventional Memory|   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000001120000000-0x00000020a0000000) (63488MB)
   efi: mem40: [Reserved           |RUN|    |  |  |  |   |  |  |  |UC] range=[0x0000000060000000-0x0000000090000000) (768MB)

And you will find that the following message is output:

   efi: Memory: 4096M/131455M mirrored memory

Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
---
 Documentation/kernel-parameters.txt |   8 ++
 arch/x86/include/asm/efi.h          |   2 +
 arch/x86/kernel/setup.c             |   4 +-
 arch/x86/platform/efi/efi.c         |   2 +-
 arch/x86/platform/efi/quirks.c      | 169 ++++++++++++++++++++++++++++++++++++
 5 files changed, 183 insertions(+), 2 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 1d6f045..0efded6 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1092,6 +1092,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			you are really sure that your UEFI does sane gc and
 			fulfills the spec otherwise your board may brick.
 
+	efi_fake_mem_mirror=nn[KMG]@ss[KMG][,nn[KMG]@ss[KMG],..] [EFI; X86]
+			Mark specific memory as mirrored memory and update
+			EFI memory map.
+			Region of memory to be marked is from ss to ss+nn.
+			Using this parameter you can do debugging of Address
+			Range Mirroring feature even if your box doesn't support
+			it.
+
 	eisa_irq_edge=	[PARISC,HW]
 			See header of drivers/parisc/eisa.c.
 
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 155162e..50e53cc 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -93,6 +93,7 @@ extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
 extern int __init efi_memblock_x86_reserve_range(void);
 extern pgd_t * __init efi_call_phys_prolog(void);
 extern void __init efi_call_phys_epilog(pgd_t *save_pgd);
+extern void __init print_efi_memmap(void);
 extern void __init efi_unmap_memmap(void);
 extern void __init efi_memory_uc(u64 addr, unsigned long size);
 extern void __init efi_map_region(efi_memory_desc_t *md);
@@ -107,6 +108,7 @@ extern void __init efi_dump_pagetable(void);
 extern void __init efi_apply_memmap_quirks(void);
 extern int __init efi_reuse_config(u64 tables, int nr_tables);
 extern void efi_delete_dummy_variable(void);
+extern void __init efi_fake_memmap(void);
 
 struct efi_setup_data {
 	u64 fw_vendor;
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 80f874b..e3ed628 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1104,8 +1104,10 @@ void __init setup_arch(char **cmdline_p)
 	memblock_set_current_limit(ISA_END_ADDRESS);
 	memblock_x86_fill();
 
-	if (efi_enabled(EFI_BOOT))
+	if (efi_enabled(EFI_BOOT)) {
+		efi_fake_memmap();
 		efi_find_mirror();
+	}
 
 	/*
 	 * The EFI specification says that boot service code won't be called
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index e4308fe..eee8068 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -222,7 +222,7 @@ int __init efi_memblock_x86_reserve_range(void)
 	return 0;
 }
 
-static void __init print_efi_memmap(void)
+void __init print_efi_memmap(void)
 {
 #ifdef EFI_DEBUG
 	efi_memory_desc_t *md;
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 1c7380d..5c785e1 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -18,6 +18,10 @@
 
 static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
 
+#define EFI_MAX_FAKE_MIRROR 8
+static struct range fake_mirrors[EFI_MAX_FAKE_MIRROR];
+static int num_fake_mirror;
+
 static bool efi_no_storage_paranoia;
 
 /*
@@ -288,3 +292,168 @@ bool efi_poweroff_required(void)
 {
 	return !!acpi_gbl_reduced_hardware;
 }
+
+void __init efi_fake_memmap(void)
+{
+	efi_memory_desc_t *md;
+	void *p, *q;
+	int i;
+	int nr_map = memmap.nr_map;
+	u64 start, end, m_start, m_end;
+	u64 new_memmap_phy;
+	void *new_memmap;
+
+	if (!num_fake_mirror)
+		return;
+
+	/* count up the number of EFI memory descriptor */
+	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+		md = p;
+		start = md->phys_addr;
+		end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1;
+
+		for (i = 0; i < num_fake_mirror; i++) {
+			/* mirroring range */
+			m_start = fake_mirrors[i].start;
+			m_end = fake_mirrors[i].end;
+
+			if (m_start <= start) {
+				/* split into 2 parts */
+				if (start < m_end && m_end < end)
+					nr_map++;
+			}
+			if (start < m_start && m_start < end) {
+				/* split into 3 parts */
+				if (m_end < end)
+					nr_map += 2;
+				/* split into 2 parts */
+				if (end <= m_end)
+					nr_map++;
+			}
+		}
+	}
+
+	/* allocate memory for new EFI memmap */
+	new_memmap_phy = memblock_alloc(memmap.desc_size * nr_map, PAGE_SIZE);
+	if (!new_memmap_phy)
+		return;
+
+	/* create new EFI memmap */
+	new_memmap = early_memremap(new_memmap_phy, memmap.desc_size * nr_map);
+	for (p = memmap.map, q = new_memmap;
+	     p < memmap.map_end;
+	     p += memmap.desc_size, q += memmap.desc_size) {
+
+		/* copy original EFI memory descriptor */
+		memcpy(q, p, memmap.desc_size);
+		md = q;
+		start = md->phys_addr;
+		end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
+
+		for (i = 0; i < num_fake_mirror; i++) {
+			/* mirroring range */
+			m_start = fake_mirrors[i].start;
+			m_end = fake_mirrors[i].end;
+
+			if (m_start <= start && end <= m_end)
+				md->attribute |= EFI_MEMORY_MORE_RELIABLE;
+
+			if (m_start <= start &&
+			    (start < m_end && m_end < end)) {
+				/* first part */
+				md->attribute |= EFI_MEMORY_MORE_RELIABLE;
+				md->num_pages = (m_end - md->phys_addr + 1) >>
+					EFI_PAGE_SHIFT;
+				/* latter part */
+				q += memmap.desc_size;
+				memcpy(q, p, memmap.desc_size);
+				md = q;
+				md->phys_addr = m_end + 1;
+				md->num_pages = (end - md->phys_addr + 1) >>
+					EFI_PAGE_SHIFT;
+			}
+
+			if ((start < m_start && m_start < end) && m_end < end) {
+				/* first part */
+				md->num_pages = (m_start - md->phys_addr) >>
+					EFI_PAGE_SHIFT;
+				/* middle part */
+				q += memmap.desc_size;
+				memcpy(q, p, memmap.desc_size);
+				md = q;
+				md->attribute |= EFI_MEMORY_MORE_RELIABLE;
+				md->phys_addr = m_start;
+				md->num_pages = (m_end - m_start + 1) >>
+					EFI_PAGE_SHIFT;
+				/* last part */
+				q += memmap.desc_size;
+				memcpy(q, p, memmap.desc_size);
+				md = q;
+				md->phys_addr = m_end + 1;
+				md->num_pages = (end - m_end) >>
+					EFI_PAGE_SHIFT;
+			}
+
+			if ((start < m_start && m_start < end) &&
+			    (end <= m_end)) {
+				/* first part */
+				md->num_pages = (m_start - md->phys_addr) >>
+					EFI_PAGE_SHIFT;
+				/* latter part */
+				q += memmap.desc_size;
+				memcpy(q, p, memmap.desc_size);
+				md = q;
+				md->phys_addr = m_start;
+				md->num_pages = (end - md->phys_addr + 1) >>
+					EFI_PAGE_SHIFT;
+				md->attribute |= EFI_MEMORY_MORE_RELIABLE;
+			}
+		}
+	}
+
+	/* swap into new EFI memmap */
+	efi_unmap_memmap();
+	memmap.map = new_memmap;
+	memmap.phys_map = (void *)new_memmap_phy;
+	memmap.nr_map = nr_map;
+	memmap.map_end = memmap.map + memmap.nr_map * memmap.desc_size;
+	set_bit(EFI_MEMMAP, &efi.flags);
+
+	/* print new EFI memmap */
+	print_efi_memmap();
+}
+
+static int __init setup_fake_mem_mirror(char *p)
+{
+	u64 start = 0, mem_size = 0;
+	int i;
+
+	if (!p)
+		return -EINVAL;
+
+	while (*p != '\0') {
+		mem_size = memparse(p, &p);
+		if (*p == '@')
+			start = memparse(p+1, &p);
+		else
+			break;
+
+		num_fake_mirror = add_range_with_merge(fake_mirrors,
+						       EFI_MAX_FAKE_MIRROR,
+						       num_fake_mirror,
+						       start,
+						       start + mem_size - 1);
+		if (*p == ',')
+			p++;
+	}
+
+	sort_range(fake_mirrors, num_fake_mirror);
+
+	for (i = 0; i < num_fake_mirror; i++)
+		pr_info("efi_fake_mem_mirror: [mem 0x%016llx-0x%016llx] marked as mirrored memory",
+			fake_mirrors[i].start, fake_mirrors[i].end);
+
+	return *p == '\0' ? 0 : -EINVAL;
+}
+
+early_param("efi_fake_mem_mirror", setup_fake_mem_mirror);
-- 
1.8.3.1

Re: [PATCH 1/2] efi: Add EFI_MEMORY_MORE_RELIABLE support to efi_md_typeattr_format()

[Matt Fleming]

On Fri, 21 Aug, at 02:15:52AM, Taku Izumi wrote:
> UEFI spec 2.5 introduces new Memory Attribute Definition named
> EFI_MEMORY_MORE_RELIABLE. This patch adds this new attribute
> support to efi_md_typeattr_format().
> 
> Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
> ---
>  drivers/firmware/efi/efi.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index d6144e3..aadc1c4 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -589,12 +589,14 @@ char * __init efi_md_typeattr_format(char *buf, size_t size,
>  	attr = md->attribute;
>  	if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
>  		     EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP |
> -		     EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME))
> +		     EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME |
> +		     EFI_MEMORY_MORE_RELIABLE))
>  		snprintf(pos, size, "|attr=0x%016llx]",
>  			 (unsigned long long)attr);
>  	else
> -		snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
> +		snprintf(pos, size, "|%3s|%4s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
>  			 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
> +			 attr & EFI_MEMORY_MORE_RELIABLE ? "RELY" : "",
>  			 attr & EFI_MEMORY_XP      ? "XP"  : "",
>  			 attr & EFI_MEMORY_RP      ? "RP"  : "",
>  			 attr & EFI_MEMORY_WP      ? "WP"  : "",

I'm not keen on using "RELY" because I don't think it's at all obvious
what it means. "RELI" would be closer, but still could use some
improvement.

Since we turned off this kernel output by default (at least on x86)
because the line length had grown quite long, maybe we should just
embrace it and print "RELIABLE" in full?

-- 
Matt Fleming, Intel Open Source Technology Center

Re: [PATCH 1/2] efi: Add EFI_MEMORY_MORE_RELIABLE support to efi_md_typeattr_format()

[Ard Biesheuvel]

On 25 August 2015 at 16:18, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> On Fri, 21 Aug, at 02:15:52AM, Taku Izumi wrote:
>> UEFI spec 2.5 introduces new Memory Attribute Definition named
>> EFI_MEMORY_MORE_RELIABLE. This patch adds this new attribute
>> support to efi_md_typeattr_format().
>>
>> Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
>> ---
>>  drivers/firmware/efi/efi.c | 6 ++++--
>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
>> index d6144e3..aadc1c4 100644
>> --- a/drivers/firmware/efi/efi.c
>> +++ b/drivers/firmware/efi/efi.c
>> @@ -589,12 +589,14 @@ char * __init efi_md_typeattr_format(char *buf, size_t size,
>>       attr = md->attribute;
>>       if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
>>                    EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP |
>> -                  EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME))
>> +                  EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME |
>> +                  EFI_MEMORY_MORE_RELIABLE))
>>               snprintf(pos, size, "|attr=0x%016llx]",
>>                        (unsigned long long)attr);
>>       else
>> -             snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
>> +             snprintf(pos, size, "|%3s|%4s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
>>                        attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
>> +                      attr & EFI_MEMORY_MORE_RELIABLE ? "RELY" : "",
>>                        attr & EFI_MEMORY_XP      ? "XP"  : "",
>>                        attr & EFI_MEMORY_RP      ? "RP"  : "",
>>                        attr & EFI_MEMORY_WP      ? "WP"  : "",
>
> I'm not keen on using "RELY" because I don't think it's at all obvious
> what it means. "RELI" would be closer, but still could use some
> improvement.
>
> Since we turned off this kernel output by default (at least on x86)
> because the line length had grown quite long, maybe we should just
> embrace it and print "RELIABLE" in full?
>

Since its meaning is not at all obvious even when printing RELIABLE in
full, couldn't we simply use 'MR' instead? You need the UEFI spec to
make sense of this anyway ... (Same goes for RUN btw, perhaps RT would
even be clearer there)

-- 
Ard.

Re: [PATCH 1/2] efi: Add EFI_MEMORY_MORE_RELIABLE support to efi_md_typeattr_format()

[Matt Fleming]

On Tue, 25 Aug, at 04:23:10PM, Ard Biesheuvel wrote:
> 
> Since its meaning is not at all obvious even when printing RELIABLE in
> full, couldn't we simply use 'MR' instead? You need the UEFI spec to
> make sense of this anyway ... (Same goes for RUN btw, perhaps RT would
> even be clearer there)

Fair point.

-- 
Matt Fleming, Intel Open Source Technology Center

Re: [PATCH 2/2] x86, efi: Add "efi_fake_mem_mirror" boot option

[Matt Fleming]

On Fri, 21 Aug, at 02:16:00AM, Taku Izumi wrote:
> This patch introduces new boot option named "efi_fake_mem_mirror".
> By specifying this parameter, you can mark specific memory as
> mirrored memory. This is useful for debugging of Address Range
> Mirroring feature.
> 
> For example, if you specify "efi_fake_mem_mirror=2G@4G,2G@0x10a0000000",
> the original (firmware provided) EFI memmap will be updated so that
> the specified memory regions have EFI_MEMORY_MORE_RELIABLE attribute:
> 
>  <original EFI memmap>
>    efi: mem00: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000000000-0x0000000000001000) (0MB)
>    efi: mem01: [Loader Data        |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000001000-0x0000000000002000) (0MB)
>    ...
>    efi: mem35: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000047ee6000-0x0000000048014000) (1MB)
>    efi: mem36: [Conventional Memory|   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x00000020a0000000) (129536MB)
>    efi: mem37: [Reserved           |RUN|    |  |  |  |   |  |  |  |UC] range=[0x0000000060000000-0x0000000090000000) (768MB)
> 
>  <updated EFI memmap>
>    efi: mem00: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000000000-0x0000000000001000) (0MB)
>    efi: mem01: [Loader Data        |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000001000-0x0000000000002000) (0MB)
>    ...
>    efi: mem35: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000047ee6000-0x0000000048014000) (1MB)
>    efi: mem36: [Conventional Memory|   |RELY|  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x0000000180000000) (2048MB)
>    efi: mem37: [Conventional Memory|   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000180000000-0x00000010a0000000) (61952MB)
>    efi: mem38: [Conventional Memory|   |RELY|  |  |  |   |WB|WT|WC|UC] range=[0x00000010a0000000-0x0000001120000000) (2048MB)
>    efi: mem39: [Conventional Memory|   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000001120000000-0x00000020a0000000) (63488MB)
>    efi: mem40: [Reserved           |RUN|    |  |  |  |   |  |  |  |UC] range=[0x0000000060000000-0x0000000090000000) (768MB)
> 
> And you will find that the following message is output:
> 
>    efi: Memory: 4096M/131455M mirrored memory
> 
> Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
> ---
>  Documentation/kernel-parameters.txt |   8 ++
>  arch/x86/include/asm/efi.h          |   2 +
>  arch/x86/kernel/setup.c             |   4 +-
>  arch/x86/platform/efi/efi.c         |   2 +-
>  arch/x86/platform/efi/quirks.c      | 169 ++++++++++++++++++++++++++++++++++++
>  5 files changed, 183 insertions(+), 2 deletions(-)

[...]

> diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
> index 1c7380d..5c785e1 100644
> --- a/arch/x86/platform/efi/quirks.c
> +++ b/arch/x86/platform/efi/quirks.c
> @@ -18,6 +18,10 @@
>  

The quirks file isn't intended to be used for this kind of feature.
It's very much a repository for workarounds for quirky firmware, i.e.
known bugs.

Instead, how about putting all this into a new fake_mem.c file? Going
further than that, there's nothing that I can see that looks
particularly x86-specific, so how about sticking all this in
drivers/firmware/efi/fake_mem.c so that the arm64 folks can make use
of it if/when they want to start playing around with
EFI_MEMORY_MORE_RELIABLE?

>  static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
>  
> +#define EFI_MAX_FAKE_MIRROR 8
> +static struct range fake_mirrors[EFI_MAX_FAKE_MIRROR];
> +static int num_fake_mirror;
> +
>  static bool efi_no_storage_paranoia;
>  
>  /*
> @@ -288,3 +292,168 @@ bool efi_poweroff_required(void)
>  {
>  	return !!acpi_gbl_reduced_hardware;
>  }
> +
> +void __init efi_fake_memmap(void)
> +{
> +	efi_memory_desc_t *md;
> +	void *p, *q;
> +	int i;
> +	int nr_map = memmap.nr_map;
> +	u64 start, end, m_start, m_end;
> +	u64 new_memmap_phy;
> +	void *new_memmap;
> +
> +	if (!num_fake_mirror)
> +		return;
> +
> +	/* count up the number of EFI memory descriptor */
> +	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
> +		md = p;
> +		start = md->phys_addr;
> +		end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1;
> +
> +		for (i = 0; i < num_fake_mirror; i++) {
> +			/* mirroring range */
> +			m_start = fake_mirrors[i].start;
> +			m_end = fake_mirrors[i].end;
> +
> +			if (m_start <= start) {
> +				/* split into 2 parts */
> +				if (start < m_end && m_end < end)
> +					nr_map++;
> +			}
> +			if (start < m_start && m_start < end) {
> +				/* split into 3 parts */
> +				if (m_end < end)
> +					nr_map += 2;
> +				/* split into 2 parts */
> +				if (end <= m_end)
> +					nr_map++;
> +			}
> +		}
> +	}
> +
> +	/* allocate memory for new EFI memmap */
> +	new_memmap_phy = memblock_alloc(memmap.desc_size * nr_map, PAGE_SIZE);
> +	if (!new_memmap_phy)
> +		return;
> +
> +	/* create new EFI memmap */
> +	new_memmap = early_memremap(new_memmap_phy, memmap.desc_size * nr_map);
> +	for (p = memmap.map, q = new_memmap;
> +	     p < memmap.map_end;
> +	     p += memmap.desc_size, q += memmap.desc_size) {

Can we rename 'p' and 'q', 'old' and 'new'? Otherwise it gets a little
tricky to follow the below code.


-- 
Matt Fleming, Intel Open Source Technology Center

RE: [PATCH 2/2] x86, efi: Add "efi_fake_mem_mirror" boot option

[Izumi, Taku]

Dear Matt,

Thank you for reviewing.

I updated my patchset.
I'm happy if you review new one.

Sincerely,
Taku Izumi

> -----Original Message-----
> From: Matt Fleming [mailto:matt@codeblueprint.co.uk]
> Sent: Wednesday, August 26, 2015 8:46 AM
> To: Izumi, Taku/泉 拓
> Cc: linux-kernel@vger.kernel.org; linux-efi@vger.kernel.org; x86@kernel.org; matt.fleming@intel.com;
> tglx@linutronix.de; mingo@redhat.com; hpa@zytor.com; tony.luck@intel.com; qiuxishi@huawei.com; Kamezawa, Hiroyuki/亀
> 澤 寛之
> Subject: Re: [PATCH 2/2] x86, efi: Add "efi_fake_mem_mirror" boot option
> 
> On Fri, 21 Aug, at 02:16:00AM, Taku Izumi wrote:
> > This patch introduces new boot option named "efi_fake_mem_mirror".
> > By specifying this parameter, you can mark specific memory as
> > mirrored memory. This is useful for debugging of Address Range
> > Mirroring feature.
> >
> > For example, if you specify "efi_fake_mem_mirror=2G@4G,2G@0x10a0000000",
> > the original (firmware provided) EFI memmap will be updated so that
> > the specified memory regions have EFI_MEMORY_MORE_RELIABLE attribute:
> >
> >  <original EFI memmap>
> >    efi: mem00: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000000000-0x0000000000001000)
> (0MB)
> >    efi: mem01: [Loader Data        |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000001000-0x0000000000002000)
> (0MB)
> >    ...
> >    efi: mem35: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000047ee6000-0x0000000048014000)
> (1MB)
> >    efi: mem36: [Conventional Memory|   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x00000020a0000000)
> (129536MB)
> >    efi: mem37: [Reserved           |RUN|    |  |  |  |   |  |  |  |UC] range=[0x0000000060000000-0x0000000090000000)
> (768MB)
> >
> >  <updated EFI memmap>
> >    efi: mem00: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000000000-0x0000000000001000)
> (0MB)
> >    efi: mem01: [Loader Data        |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000001000-0x0000000000002000)
> (0MB)
> >    ...
> >    efi: mem35: [Boot Data          |   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000047ee6000-0x0000000048014000)
> (1MB)
> >    efi: mem36: [Conventional Memory|   |RELY|  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x0000000180000000)
> (2048MB)
> >    efi: mem37: [Conventional Memory|   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000000180000000-0x00000010a0000000)
> (61952MB)
> >    efi: mem38: [Conventional Memory|   |RELY|  |  |  |   |WB|WT|WC|UC] range=[0x00000010a0000000-0x0000001120000000)
> (2048MB)
> >    efi: mem39: [Conventional Memory|   |    |  |  |  |   |WB|WT|WC|UC] range=[0x0000001120000000-0x00000020a0000000)
> (63488MB)
> >    efi: mem40: [Reserved           |RUN|    |  |  |  |   |  |  |  |UC] range=[0x0000000060000000-0x0000000090000000)
> (768MB)
> >
> > And you will find that the following message is output:
> >
> >    efi: Memory: 4096M/131455M mirrored memory
> >
> > Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
> > ---
> >  Documentation/kernel-parameters.txt |   8 ++
> >  arch/x86/include/asm/efi.h          |   2 +
> >  arch/x86/kernel/setup.c             |   4 +-
> >  arch/x86/platform/efi/efi.c         |   2 +-
> >  arch/x86/platform/efi/quirks.c      | 169 ++++++++++++++++++++++++++++++++++++
> >  5 files changed, 183 insertions(+), 2 deletions(-)
> 
> [...]
> 
> > diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
> > index 1c7380d..5c785e1 100644
> > --- a/arch/x86/platform/efi/quirks.c
> > +++ b/arch/x86/platform/efi/quirks.c
> > @@ -18,6 +18,10 @@
> >
> 
> The quirks file isn't intended to be used for this kind of feature.
> It's very much a repository for workarounds for quirky firmware, i.e.
> known bugs.
> 
> Instead, how about putting all this into a new fake_mem.c file? Going
> further than that, there's nothing that I can see that looks
> particularly x86-specific, so how about sticking all this in
> drivers/firmware/efi/fake_mem.c so that the arm64 folks can make use
> of it if/when they want to start playing around with
> EFI_MEMORY_MORE_RELIABLE?
> 
> >  static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
> >
> > +#define EFI_MAX_FAKE_MIRROR 8
> > +static struct range fake_mirrors[EFI_MAX_FAKE_MIRROR];
> > +static int num_fake_mirror;
> > +
> >  static bool efi_no_storage_paranoia;
> >
> >  /*
> > @@ -288,3 +292,168 @@ bool efi_poweroff_required(void)
> >  {
> >  	return !!acpi_gbl_reduced_hardware;
> >  }
> > +
> > +void __init efi_fake_memmap(void)
> > +{
> > +	efi_memory_desc_t *md;
> > +	void *p, *q;
> > +	int i;
> > +	int nr_map = memmap.nr_map;
> > +	u64 start, end, m_start, m_end;
> > +	u64 new_memmap_phy;
> > +	void *new_memmap;
> > +
> > +	if (!num_fake_mirror)
> > +		return;
> > +
> > +	/* count up the number of EFI memory descriptor */
> > +	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
> > +		md = p;
> > +		start = md->phys_addr;
> > +		end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1;
> > +
> > +		for (i = 0; i < num_fake_mirror; i++) {
> > +			/* mirroring range */
> > +			m_start = fake_mirrors[i].start;
> > +			m_end = fake_mirrors[i].end;
> > +
> > +			if (m_start <= start) {
> > +				/* split into 2 parts */
> > +				if (start < m_end && m_end < end)
> > +					nr_map++;
> > +			}
> > +			if (start < m_start && m_start < end) {
> > +				/* split into 3 parts */
> > +				if (m_end < end)
> > +					nr_map += 2;
> > +				/* split into 2 parts */
> > +				if (end <= m_end)
> > +					nr_map++;
> > +			}
> > +		}
> > +	}
> > +
> > +	/* allocate memory for new EFI memmap */
> > +	new_memmap_phy = memblock_alloc(memmap.desc_size * nr_map, PAGE_SIZE);
> > +	if (!new_memmap_phy)
> > +		return;
> > +
> > +	/* create new EFI memmap */
> > +	new_memmap = early_memremap(new_memmap_phy, memmap.desc_size * nr_map);
> > +	for (p = memmap.map, q = new_memmap;
> > +	     p < memmap.map_end;
> > +	     p += memmap.desc_size, q += memmap.desc_size) {
> 
> Can we rename 'p' and 'q', 'old' and 'new'? Otherwise it gets a little
> tricky to follow the below code.
> 
> 
> --
> Matt Fleming, Intel Open Source Technology Center