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[Qemu-devel] [PATCH 27/31] kvm: x86: Rework identity map and TSS setup f
From: |
Marcelo Tosatti |
Subject: |
[Qemu-devel] [PATCH 27/31] kvm: x86: Rework identity map and TSS setup for larger BIOS sizes |
Date: |
Mon, 24 Jan 2011 07:02:36 -0200 |
From: Jan Kiszka <address@hidden>
In order to support loading BIOSes > 256K, reorder the code, adjusting
the base if the kernel supports moving the identity map.
Signed-off-by: Jan Kiszka <address@hidden>
Signed-off-by: Marcelo Tosatti <address@hidden>
---
target-i386/kvm.c | 63 +++++++++++++++++++++++++---------------------------
1 files changed, 30 insertions(+), 33 deletions(-)
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 1db8227..72f9fdf 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -493,27 +493,9 @@ static int kvm_get_supported_msrs(KVMState *s)
return ret;
}
-static int kvm_init_identity_map_page(KVMState *s)
-{
-#ifdef KVM_CAP_SET_IDENTITY_MAP_ADDR
- int ret;
- uint64_t addr = 0xfffbc000;
-
- if (!kvm_check_extension(s, KVM_CAP_SET_IDENTITY_MAP_ADDR)) {
- return 0;
- }
-
- ret = kvm_vm_ioctl(s, KVM_SET_IDENTITY_MAP_ADDR, &addr);
- if (ret < 0) {
- fprintf(stderr, "kvm_set_identity_map_addr: %s\n", strerror(ret));
- return ret;
- }
-#endif
- return 0;
-}
-
int kvm_arch_init(KVMState *s)
{
+ uint64_t identity_base = 0xfffbc000;
int ret;
struct utsname utsname;
@@ -525,27 +507,42 @@ int kvm_arch_init(KVMState *s)
uname(&utsname);
lm_capable_kernel = strcmp(utsname.machine, "x86_64") == 0;
- /* create vm86 tss. KVM uses vm86 mode to emulate 16-bit code
- * directly. In order to use vm86 mode, a TSS is needed. Since this
- * must be part of guest physical memory, we need to allocate it. */
-
- /* this address is 3 pages before the bios, and the bios should present
- * as unavaible memory. FIXME, need to ensure the e820 map deals with
- * this?
- */
/*
- * Tell fw_cfg to notify the BIOS to reserve the range.
+ * On older Intel CPUs, KVM uses vm86 mode to emulate 16-bit code directly.
+ * In order to use vm86 mode, an EPT identity map and a TSS are needed.
+ * Since these must be part of guest physical memory, we need to allocate
+ * them, both by setting their start addresses in the kernel and by
+ * creating a corresponding e820 entry. We need 4 pages before the BIOS.
+ *
+ * Older KVM versions may not support setting the identity map base. In
+ * that case we need to stick with the default, i.e. a 256K maximum BIOS
+ * size.
*/
- if (e820_add_entry(0xfffbc000, 0x4000, E820_RESERVED) < 0) {
- perror("e820_add_entry() table is full");
- exit(1);
+#ifdef KVM_CAP_SET_IDENTITY_MAP_ADDR
+ if (kvm_check_extension(s, KVM_CAP_SET_IDENTITY_MAP_ADDR)) {
+ /* Allows up to 16M BIOSes. */
+ identity_base = 0xfeffc000;
+
+ ret = kvm_vm_ioctl(s, KVM_SET_IDENTITY_MAP_ADDR, &identity_base);
+ if (ret < 0) {
+ return ret;
+ }
}
- ret = kvm_vm_ioctl(s, KVM_SET_TSS_ADDR, 0xfffbd000);
+#endif
+ /* Set TSS base one page after EPT identity map. */
+ ret = kvm_vm_ioctl(s, KVM_SET_TSS_ADDR, identity_base + 0x1000);
+ if (ret < 0) {
+ return ret;
+ }
+
+ /* Tell fw_cfg to notify the BIOS to reserve the range. */
+ ret = e820_add_entry(identity_base, 0x4000, E820_RESERVED);
if (ret < 0) {
+ fprintf(stderr, "e820_add_entry() table is full\n");
return ret;
}
- return kvm_init_identity_map_page(s);
+ return 0;
}
static void set_v8086_seg(struct kvm_segment *lhs, const SegmentCache *rhs)
--
1.7.2.3
- [Qemu-devel] [PATCH 13/31] kvm: Fix coding style violations, (continued)
- [Qemu-devel] [PATCH 13/31] kvm: Fix coding style violations, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 08/31] kvm: introduce kvm_inject_x86_mce_on, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 14/31] kvm: x86: Swallow KVM_EXIT_SET_TPR, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 09/31] kvm: x86: Fix DPL write back of segment registers, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 29/31] kvm: Do not use qemu_fair_mutex, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 18/31] kvm: x86: Align kvm_arch_put_registers code with comment, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 10/31] kvm: x86: Remove obsolete SS.RPL/DPL aligment, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 21/31] kvm: x86: Fix xcr0 reset mismerge, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 20/31] kvm: x86: Remove redundant mp_state initialization, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 23/31] kvm: x86: Reset paravirtual MSRs, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 27/31] kvm: x86: Rework identity map and TSS setup for larger BIOS sizes,
Marcelo Tosatti <=
- [Qemu-devel] [PATCH 25/31] kvm: Drop smp_cpus argument from init functions, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 16/31] kvm: Improve reporting of fatal errors, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 06/31] kvm: introduce kvm_mce_in_progress, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 12/31] kvm: x86: Fix a few coding style violations, Marcelo Tosatti, 2011/01/24
- [Qemu-devel] [PATCH 26/31] kvm: Consolidate must-have capability checks, Marcelo Tosatti, 2011/01/24