kvm: Clean up reset vector setup code

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

diff --git a/tools/kvm/include/kvm/kvm.h b/tools/kvm/include/kvm/kvm.h
index a51b38de2df95a65b82adb969fc45c14d69c6a1c..d3f6ac86f801494c827ecc9e38457239a4006316 100644 (file)
--- a/tools/kvm/include/kvm/kvm.h
+++ b/tools/kvm/include/kvm/kvm.h
@@ -15,9 +15,6 @@ struct kvm {
        uint64_t                ram_size;
        void                    *ram_start;
 
-       uint16_t                boot_cs;        /* 16-bit code segment selector */
-       uint16_t                boot_ip;        /* 16-bit code offset */
-
        struct kvm_regs         regs;
        struct kvm_sregs        sregs;
 };

diff --git a/tools/kvm/kvm.c b/tools/kvm/kvm.c
index 5b241137cc232dd9db19918a7b8fbd66daeecc09..e922b93804c83be3c606490fe8edc926e507fd8a 100644 (file)
--- a/tools/kvm/kvm.c
+++ b/tools/kvm/kvm.c
@@ -153,13 +153,22 @@ static inline uint32_t segment_to_flat(uint16_t selector, uint16_t offset)
        return ((uint32_t)selector << 4) + (uint32_t) offset;
 }
 
-#define RESET_CS               0xf000
-#define RESET_IP               0xfff0
+#define RESET_VECTOR_CS                0xf000
+#define RESET_VECTOR_IP                0xfff0
 
-#define BIN_BOOT_LOADER_CS     0x0000
-#define BIN_BOOT_LOADER_IP     0x7c00
+static unsigned char reset_vector_code[] = { 0xea, 0x00, 0x7c, 0x00, 0x00 };
 
-static unsigned char reset_code[] = { 0xea, 0x00, 0x7c, 0x00, 0x00 };
+static void load_reset_vector(struct kvm *self)
+{
+       void *p;
+
+       p       = guest_addr_to_host(self, segment_to_flat(RESET_VECTOR_CS, RESET_VECTOR_IP));
+
+       memcpy(p, reset_vector_code, ARRAY_SIZE(reset_vector_code));
+}
+
+#define BOOT_LOADER_CS         0x0000
+#define BOOT_LOADER_IP         0x7c00
 
 static int load_flat_binary(struct kvm *kvm, int fd)
 {
@@ -169,32 +178,14 @@ static int load_flat_binary(struct kvm *kvm, int fd)
        if (lseek(fd, 0, SEEK_SET) < 0)
                die_perror("lseek");
 
-       p = guest_addr_to_host(kvm, segment_to_flat(BIN_BOOT_LOADER_CS, BIN_BOOT_LOADER_IP));
+       p = guest_addr_to_host(kvm, segment_to_flat(BOOT_LOADER_CS, BOOT_LOADER_IP));
 
        while ((nr = read(fd, p, 65536)) > 0)
                p += nr;
 
-       p = guest_addr_to_host(kvm, segment_to_flat(RESET_CS, RESET_IP));
-
-       memcpy(p, reset_code, ARRAY_SIZE(reset_code));
-
-       kvm->boot_cs    = RESET_CS;
-       kvm->boot_ip    = RESET_IP;
-
        return true;
 }
 
-/*
- * See Documentation/x86/boot.txt for details no how a bzImage is laid out in
- * memory.
- */
-
-/*
- * As we emulate the boot loader, we can load kernel boot sector and setup code
- * at the address which usually has the boot loader.
- */
-#define BZ_BOOT_LOADER_START           0x007c00UL
-
 /*
  * The protected mode kernel part of a modern bzImage is loaded at 1 MB by
  * default.
@@ -213,6 +204,11 @@ static bool load_bzimage(struct kvm *kvm, int fd)
        void *p;
        int nr;
 
+       /*
+        * See Documentation/x86/boot.txt for details no bzImage on-disk and
+        * memory layout.
+        */
+
        if (lseek(fd, 0, SEEK_SET) < 0)
                die_perror("lseek");
 
@@ -229,7 +225,7 @@ static bool load_bzimage(struct kvm *kvm, int fd)
                setup_sects      = BZ_DEFAULT_SETUP_SECTS;
 
        setup_size = setup_sects << 4;
-       p = guest_addr_to_host(kvm, BZ_BOOT_LOADER_START);
+       p = guest_addr_to_host(kvm, segment_to_flat(BOOT_LOADER_CS, BOOT_LOADER_IP));
 
        if (read(fd, p, setup_size) != setup_size)
                die_perror("read");
@@ -239,13 +235,6 @@ static bool load_bzimage(struct kvm *kvm, int fd)
        while ((nr = read(fd, p, 65536)) > 0)
                p += nr;
 
-       p = guest_addr_to_host(kvm, segment_to_flat(RESET_CS, RESET_IP));
-
-       memcpy(p, reset_code, ARRAY_SIZE(reset_code));
-
-       kvm->boot_cs    = RESET_CS;
-       kvm->boot_ip    = RESET_IP;
-
        return true;
 }
 
@@ -288,10 +277,12 @@ static inline uint64_t ip_real_to_flat(struct kvm *self, uint64_t ip)
 
 void kvm__reset_vcpu(struct kvm *self)
 {
+       load_reset_vector(self);
+
        self->sregs = (struct kvm_sregs) {
                .cr0            = 0x60000010ULL,
                .cs             = (struct kvm_segment) {
-                       .selector       = self->boot_cs,
+                       .selector       = RESET_VECTOR_CS,
                        .base           = 0xffff0000UL,
                        .limit          = 0xffffU,
                        .type           = 0x0bU,
@@ -356,7 +347,7 @@ void kvm__reset_vcpu(struct kvm *self)
                die_perror("KVM_SET_SREGS failed");
 
        self->regs = (struct kvm_regs) {
-               .rip            = self->boot_ip,
+               .rip            = RESET_VECTOR_IP,
                /* We start the guest in 16-bit real mode  */
                .rflags         = 0x0000000000000002ULL,
        };