[PATCH] QEMU-KVM - provide e820 table via fw_cfg

Jes Sorensen
2010-01-26T21:54:03Z

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Hi,

This is the QEMU-KVM part of the patch. If we can agree on this
approach, I will do a version for upstream QEMU as well.

Cheers,
Jes

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Use qemu-cfg to provide the BIOS with an optional table of e820 entries.

Notify the BIOS of the location of the TSS+EPT range to by reserving
it via the e820 table.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>

---
hw/pc.c | 35 +++++++++++++++++++++++++++++++++++
hw/pc.h | 9 +++++++++
qemu-kvm-x86.c | 7 +++++++
target-i386/kvm.c | 7 +++++++
4 files changed, 58 insertions(+)

Index: qemu-kvm/hw/pc.c
===================================================================
--- qemu-kvm.orig/hw/pc.c
+++ qemu-kvm/hw/pc.c
@@ -66,6 +66,7 @@
#define FW_CFG_ACPI_TABLES (FW_CFG_ARCH_LOCAL + 0)
#define FW_CFG_SMBIOS_ENTRIES (FW_CFG_ARCH_LOCAL + 1)
#define FW_CFG_IRQ0_OVERRIDE (FW_CFG_ARCH_LOCAL + 2)
+#define FW_CFG_E820_TABLE (FW_CFG_ARCH_LOCAL + 3)

#define MAX_IDE_BUS 2

@@ -74,6 +75,21 @@ static RTCState *rtc_state;
static PITState *pit;
static PCII440FXState *i440fx_state;

+#define E820_NR_ENTRIES 16
+
+struct e820_entry {
+ uint64_t address;
+ uint64_t length;
+ uint32_t type;
+};
+
+struct e820_table {
+ uint32_t count;
+ struct e820_entry entry[E820_NR_ENTRIES];
+};
+
+static struct e820_table e820_table;
+
qemu_irq *ioapic_irq_hack;

typedef struct isa_irq_state {
@@ -444,6 +460,23 @@ static void bochs_bios_write(void *opaqu
}
}

+int e820_add_entry(uint64_t address, uint64_t length, uint32_t type)
+{
+ int index = e820_table.count;
+ struct e820_entry *entry;
+
+ if (index >= E820_NR_ENTRIES)
+ return -EBUSY;
+ entry = &e820_table.entry[index];
+
+ entry->address = address;
+ entry->length = length;
+ entry->type = type;
+
+ e820_table.count++;
+ return e820_table.count;
+}
+
static void *bochs_bios_init(void)
{
void *fw_cfg;
@@ -475,6 +508,8 @@ static void *bochs_bios_init(void)
if (smbios_table)
fw_cfg_add_bytes(fw_cfg, FW_CFG_SMBIOS_ENTRIES,
smbios_table, smbios_len);
+ fw_cfg_add_bytes(fw_cfg, FW_CFG_E820_TABLE, (uint8_t *)&e820_table,
+ sizeof(struct e820_table));

/* allocate memory for the NUMA channel: one (64bit) word for the number
* of nodes, one word for each VCPU->node and one word for each node to
Index: qemu-kvm/hw/pc.h
===================================================================
--- qemu-kvm.orig/hw/pc.h
+++ qemu-kvm/hw/pc.h
@@ -169,4 +169,13 @@ void extboot_init(BlockDriverState *bs,

int cpu_is_bsp(CPUState *env);

+/* e820 types */
+#define E820_RAM 1
+#define E820_RESERVED 2
+#define E820_ACPI 3
+#define E820_NVS 4
+#define E820_UNUSABLE 5
+
+int e820_add_entry(uint64_t, uint64_t, uint32_t);
+
#endif
Index: qemu-kvm/qemu-kvm-x86.c
===================================================================
--- qemu-kvm.orig/qemu-kvm-x86.c
+++ qemu-kvm/qemu-kvm-x86.c
@@ -37,6 +37,13 @@ int kvm_set_tss_addr(kvm_context_t kvm,
{
#ifdef KVM_CAP_SET_TSS_ADDR
int r;
+ /*
+ * Tell fw_cfg to notify the BIOS to reserve the range.
+ */
+ if (e820_add_entry(addr, 0x4000, E820_RESERVED) < 0) {
+ perror("e820_add_entry() table is full");
+ exit(1);
+ }

r = kvm_ioctl(kvm_state, KVM_CHECK_EXTENSION, KVM_CAP_SET_TSS_ADDR);
if (r > 0) {
Index: qemu-kvm/target-i386/kvm.c
===================================================================
--- qemu-kvm.orig/target-i386/kvm.c
+++ qemu-kvm/target-i386/kvm.c
@@ -298,6 +298,13 @@ int kvm_arch_init(KVMState *s, int smp_c
* as unavaible memory. FIXME, need to ensure the e820 map deals with
* this?
*/
+ /*
+ * Tell fw_cfg to notify the BIOS to reserve the range.
+ */
+ if (e820_add_entry(0xfffbc000, 0x4000, E820_RESERVED) < 0) {
+ perror("e820_add_entry() table is full");
+ exit(1);
+ }
return kvm_vm_ioctl(s, KVM_SET_TSS_ADDR, 0xfffbd000);
}