[PATCH] kvm tools: Cleanup e820 code

[PATCH] kvm tools: Cleanup e820 code

[Sasha Levin]

Several cleanups in the patch:
 - Use kernel headers for e820 types and definitions.
 - A byte sized entry count for e820 enteries was used,
this should be dword sized. Update in-memory layout and
bios code to fix it.
 - Use struct e820map to calculate offsets used by bios code.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
---
 tools/kvm/bios.c             |   37 +++++++++++++++++++------------------
 tools/kvm/bios/e820.c        |   29 +++++++++++++++++++++--------
 tools/kvm/include/kvm/bios.h |    3 +--
 tools/kvm/include/kvm/e820.h |   11 -----------
 4 files changed, 41 insertions(+), 39 deletions(-)

diff --git a/tools/kvm/bios.c b/tools/kvm/bios.c
index 3cd9b24..94e914c 100644
--- a/tools/kvm/bios.c
+++ b/tools/kvm/bios.c
@@ -5,6 +5,7 @@
 #include "kvm/util.h"
 
 #include <string.h>
+#include <asm/e820.h>
 
 #include "bios/bios-rom.h"
 
@@ -54,50 +55,50 @@ static void setup_irq_handler(struct kvm *kvm, struct irq_handler *handler)
  */
 static void e820_setup(struct kvm *kvm)
 {
-	struct e820_entry *mem_map;
-	unsigned char *size;
+	struct e820map *e820;
+	struct e820entry *mem_map;
 	unsigned int i = 0;
 
-	size		= guest_flat_to_host(kvm, E820_MAP_SIZE);
-	mem_map		= guest_flat_to_host(kvm, E820_MAP_START);
+	e820		= guest_flat_to_host(kvm, E820_MAP_START);
+	mem_map		= e820->map;
 
-	mem_map[i++]	= (struct e820_entry) {
+	mem_map[i++]	= (struct e820entry) {
 		.addr		= REAL_MODE_IVT_BEGIN,
 		.size		= EBDA_START - REAL_MODE_IVT_BEGIN,
-		.type		= E820_MEM_USABLE,
+		.type		= E820_RAM,
 	};
-	mem_map[i++]	= (struct e820_entry) {
+	mem_map[i++]	= (struct e820entry) {
 		.addr		= EBDA_START,
 		.size		= VGA_RAM_BEGIN - EBDA_START,
-		.type		= E820_MEM_RESERVED,
+		.type		= E820_RESERVED,
 	};
-	mem_map[i++]	= (struct e820_entry) {
+	mem_map[i++]	= (struct e820entry) {
 		.addr		= MB_BIOS_BEGIN,
 		.size		= MB_BIOS_END - MB_BIOS_BEGIN,
-		.type		= E820_MEM_RESERVED,
+		.type		= E820_RESERVED,
 	};
 	if (kvm->ram_size < KVM_32BIT_GAP_START) {
-		mem_map[i++]	= (struct e820_entry) {
+		mem_map[i++]	= (struct e820entry) {
 			.addr		= BZ_KERNEL_START,
 			.size		= kvm->ram_size - BZ_KERNEL_START,
-			.type		= E820_MEM_USABLE,
+			.type		= E820_RAM,
 		};
 	} else {
-		mem_map[i++]	= (struct e820_entry) {
+		mem_map[i++]	= (struct e820entry) {
 			.addr		= BZ_KERNEL_START,
 			.size		= KVM_32BIT_GAP_START - BZ_KERNEL_START,
-			.type		= E820_MEM_USABLE,
+			.type		= E820_RAM,
 		};
-		mem_map[i++]	= (struct e820_entry) {
+		mem_map[i++]	= (struct e820entry) {
 			.addr		= 0x100000000ULL,
 			.size		= kvm->ram_size - KVM_32BIT_GAP_START,
-			.type		= E820_MEM_USABLE,
+			.type		= E820_RAM,
 		};
 	}
 
-	BUILD_BUG_ON(i > E820_MEM_AREAS);
+	BUILD_BUG_ON(i > E820_X_MAX);
 
-	*size			= i;
+	e820->nr_map			= i;
 }
 
 /**
diff --git a/tools/kvm/bios/e820.c b/tools/kvm/bios/e820.c
index e4d8354..b7fa4c1 100644
--- a/tools/kvm/bios/e820.c
+++ b/tools/kvm/bios/e820.c
@@ -4,6 +4,8 @@
 #include "kvm/bios.h"
 #include "kvm/util.h"
 
+#include <asm/e820.h>
+
 static inline void set_fs(u16 seg)
 {
 	asm volatile("movw %0,%%fs" : : "rm" (seg));
@@ -18,37 +20,48 @@ static inline u8 rdfs8(unsigned long addr)
 	return v;
 }
 
+static inline u32 rdfs32(unsigned long addr)
+{
+	u32 v;
+
+	asm volatile("addr32 movl %%fs:%1,%0" : "=q" (v) : "m" (*(u32 *)addr));
+
+	return v;
+}
+
 bioscall void e820_query_map(struct e820_query *query)
 {
-	u8 map_size;
+	struct e820map *e820;
+	u32 map_size;
 	u16 fs_seg;
 	u32 ndx;
 
-	fs_seg		= flat_to_seg16(E820_MAP_SIZE);
+	e820		= (struct e820map *)E820_MAP_START;
+	fs_seg		= flat_to_seg16(E820_MAP_START);
 	set_fs(fs_seg);
 
 	ndx		= query->ebx;
 
-	map_size	= rdfs8(flat_to_off16(E820_MAP_SIZE, fs_seg));
+	map_size	= rdfs32(flat_to_off16((u32)&e820->nr_map, fs_seg));
 
 	if (ndx < map_size) {
-		unsigned long start;
+		u32 start;
 		unsigned int i;
 		u8 *p;
 
-		fs_seg		= flat_to_seg16(E820_MAP_START);
+		fs_seg	= flat_to_seg16(E820_MAP_START);
 		set_fs(fs_seg);
 
-		start	= E820_MAP_START + sizeof(struct e820_entry) * ndx;
+		start	= (u32)&e820->map[ndx];
 
 		p	= (void *) query->edi;
 
-		for (i = 0; i < sizeof(struct e820_entry); i++)
+		for (i = 0; i < sizeof(struct e820entry); i++)
 			*p++	= rdfs8(flat_to_off16(start + i, fs_seg));
 	}
 
 	query->eax	= SMAP;
-	query->ecx	= sizeof(struct e820_entry);
+	query->ecx	= sizeof(struct e820entry);
 	query->ebx	= ++ndx;
 
 	if (ndx >= map_size)
diff --git a/tools/kvm/include/kvm/bios.h b/tools/kvm/include/kvm/bios.h
index 7586e2a..9db2ab5 100644
--- a/tools/kvm/include/kvm/bios.h
+++ b/tools/kvm/include/kvm/bios.h
@@ -24,8 +24,7 @@
 #define EBDA_START			0x0009fc00
 #define EBDA_END			0x0009ffff
 
-#define E820_MAP_SIZE			EBDA_START
-#define E820_MAP_START			(EBDA_START + 0x01)
+#define E820_MAP_START			EBDA_START
 
 #define MB_BIOS_BEGIN			0x000f0000
 #define MB_BIOS_END			0x000fffff
diff --git a/tools/kvm/include/kvm/e820.h b/tools/kvm/include/kvm/e820.h
index e0f5f2a..9b339ed 100644
--- a/tools/kvm/include/kvm/e820.h
+++ b/tools/kvm/include/kvm/e820.h
@@ -5,17 +5,6 @@
 
 #define SMAP    0x534d4150      /* ASCII "SMAP" */
 
-#define E820_MEM_USABLE		1
-#define E820_MEM_RESERVED	2
-
-#define E820_MEM_AREAS		5
-
-struct e820_entry {
-	u64	addr;	/* start of memory segment */
-	u64	size;	/* size of memory segment */
-	u32	type;	/* type of memory segment */
-} __attribute__((packed));
-
 struct e820_query {
 	u32	eax;
 	u32	ebx;
-- 
1.7.5.rc3

Re: [PATCH] kvm tools: Cleanup e820 code

[Cyrill Gorcunov]

On 05/20/2011 06:23 PM, Sasha Levin wrote:
> Several cleanups in the patch:
>  - Use kernel headers for e820 types and definitions.
>  - A byte sized entry count for e820 enteries was used,
> this should be dword sized. Update in-memory layout and
> bios code to fix it.
>  - Use struct e820map to calculate offsets used by bios code.
> 
> Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
> ---

Thanks Sasha!

Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>

-- 
            Cyrill