[Qemu-devel] [PATCH 0/5] Seabios qemu detect

[Qemu-devel] [PATCH 0/5] Seabios qemu detect

[Jes Sorensen]

Hi,

Argh! Forgot to post this yesterday!

Here is a series of patches for Seabios which introduces support for
QEMU_CFG_EMULATOR and uses it to select the irq0verride flag and for
runtime detection of whether or not Seabios is running on QEMU and
KVM.

This allows us to eliminate CONFIG_KVM completely as well.

I would love to see something similar used to detect Coreboot, making
it possible to have one shared BIOS binary.

Cheers,
Jes

[Qemu-devel] [PATCH 1/5] Move QEMU_CFG related code out of smbios.c

[Jes Sorensen]

[-- Attachment #1: 0002-seperate-qemu-cfg.patch --]
[-- Type: text/plain, Size: 3493 bytes --]

This patch moves QEMU_CFG infrastructure out of smbios.c and puts it
into seperate files.

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

---
 Makefile       |    4 ++--
 src/qemu-cfg.c |   29 +++++++++++++++++++++++++++++
 src/qemu-cfg.h |   19 +++++++++++++++++++
 src/smbios.c   |   22 +---------------------
 4 files changed, 51 insertions(+), 23 deletions(-)

Index: seabios/Makefile
===================================================================
--- seabios.orig/Makefile
+++ seabios/Makefile
@@ -16,8 +16,8 @@ SRCBOTH=output.c util.c floppy.c ata.c m
         pnpbios.c pirtable.c vgahooks.c pmm.c
 SRC16=$(SRCBOTH) system.c disk.c apm.c pcibios.c font.c
 SRC32=$(SRCBOTH) post.c shadow.c memmap.c coreboot.c boot.c \
-      acpi.c smm.c mptable.c smbios.c pciinit.c optionroms.c mtrr.c \
-      lzmadecode.c
+      acpi.c smm.c mptable.c qemu-cfg.c smbios.c pciinit.c optionroms.c \
+      mtrr.c lzmadecode.c
 
 cc-option = $(shell if test -z "`$(1) $(2) -S -o /dev/null -xc \
               /dev/null 2>&1`"; then echo "$(2)"; else echo "$(3)"; fi ;)
Index: seabios/src/qemu-cfg.c
===================================================================
--- /dev/null
+++ seabios/src/qemu-cfg.c
@@ -0,0 +1,29 @@
+// qemu-cfg.c: QEMU_CFG related code
+//
+// Copyright (C) 2009  Jes Sorensen, SGI <jes@sgi.com>
+// Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2006 Fabrice Bellard
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#include "types.h"
+#include "ioport.h"
+#include "qemu-cfg.h"
+
+void
+qemu_cfg_read(u8 *buf, u16 f, int len)
+{
+    outw(f, PORT_QEMU_CFG_CTL);
+    while (len--)
+        *(buf++) = inb(PORT_QEMU_CFG_DATA);
+}
+
+int
+qemu_cfg_port_probe()
+{
+    u8 sig[4] = "QEMU";
+    u8 buf[4];
+    qemu_cfg_read(buf, QEMU_CFG_SIGNATURE, 4);
+    return *(u32*)buf == *(u32*)sig;
+}
+
Index: seabios/src/qemu-cfg.h
===================================================================
--- /dev/null
+++ seabios/src/qemu-cfg.h
@@ -0,0 +1,19 @@
+// qemu-cfg.h: QEMU_CFG related definitions
+//
+// Copyright (C) 2009  Jes Sorensen, SGI <jes@sgi.com>
+// Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2006 Fabrice Bellard
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#ifndef __QEMU_CFG_H
+#define __QEMU_CFG_H
+
+#define QEMU_CFG_SIGNATURE  0x00
+#define QEMU_CFG_ID         0x01
+#define QEMU_CFG_UUID       0x02
+
+void qemu_cfg_read(u8 *buf, u16 f, int len);
+int qemu_cfg_port_probe();
+
+#endif
Index: seabios/src/smbios.c
===================================================================
--- seabios.orig/src/smbios.c
+++ seabios/src/smbios.c
@@ -8,33 +8,13 @@
 #include "util.h" // dprintf
 #include "memmap.h" // malloc_fseg
 #include "biosvar.h" // GET_EBDA
+#include "qemu-cfg.h" // QEMU_CFG_UUID
 
 
 /****************************************************************
  * UUID probe
  ****************************************************************/
 
-#define QEMU_CFG_SIGNATURE  0x00
-#define QEMU_CFG_ID         0x01
-#define QEMU_CFG_UUID       0x02
-
-static void
-qemu_cfg_read(u8 *buf, u16 f, int len)
-{
-    outw(f, PORT_QEMU_CFG_CTL);
-    while (len--)
-        *(buf++) = inb(PORT_QEMU_CFG_DATA);
-}
-
-static int
-qemu_cfg_port_probe()
-{
-    u8 sig[4] = "QEMU";
-    u8 buf[4];
-    qemu_cfg_read(buf, QEMU_CFG_SIGNATURE, 4);
-    return *(u32*)buf == *(u32*)sig;
-}
-
 static void
 uuid_probe(u8 *bios_uuid)
 {

[Qemu-devel] [PATCH 2/5] Reorder call for qemu-cfg probing.

[Jes Sorensen]

[-- Attachment #1: 0003-reorder-cfg-probe.patch --]
[-- Type: text/plain, Size: 2351 bytes --]

This moves the call to probe for qemu-cfg to an earlier point in the
BIOS init. Required in order to use the output for mptable setup etc.

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

---
 src/post.c     |   10 ++++++++++
 src/qemu-cfg.c |    6 +++++-
 src/smbios.c   |    2 +-
 src/util.h     |    3 +++
 4 files changed, 19 insertions(+), 2 deletions(-)

Index: seabios/src/post.c
===================================================================
--- seabios.orig/src/post.c
+++ seabios/src/post.c
@@ -18,6 +18,7 @@
 #include "bregs.h" // struct bregs
 #include "mptable.h" // mptable_init
 #include "boot.h" // IPL
+#include "qemu-cfg.h"
 
 void
 __set_irq(int vector, void *loc)
@@ -158,6 +159,15 @@ post()
     init_ivt();
     init_bda();
 
+    /*
+     * Test for emulator earlier, to be able to runtime check whether
+     * we are on QEMU/KVM/Coreboot etc.
+     *
+     * Would be ideal to be able to runtime test for coreboot in here,
+     * if someone knows how to do so reliably.
+     */
+    qemu_cfg_port_probe();
+
     pic_setup();
     timer_setup();
     mathcp_setup();
Index: seabios/src/qemu-cfg.c
===================================================================
--- seabios.orig/src/qemu-cfg.c
+++ seabios/src/qemu-cfg.c
@@ -10,6 +10,8 @@
 #include "ioport.h"
 #include "qemu-cfg.h"
 
+int qemu_cfg_port = 0;
+
 void
 qemu_cfg_read(u8 *buf, u16 f, int len)
 {
@@ -24,6 +26,8 @@ qemu_cfg_port_probe()
     u8 sig[4] = "QEMU";
     u8 buf[4];
     qemu_cfg_read(buf, QEMU_CFG_SIGNATURE, 4);
-    return *(u32*)buf == *(u32*)sig;
+    if (*(u32*)buf == *(u32*)sig)
+        qemu_cfg_port = 1;
+    return qemu_cfg_port;
 }
 
Index: seabios/src/smbios.c
===================================================================
--- seabios.orig/src/smbios.c
+++ seabios/src/smbios.c
@@ -24,7 +24,7 @@ uuid_probe(u8 *bios_uuid)
         return;
     if (CONFIG_COREBOOT)
         return;
-    if (! qemu_cfg_port_probe())
+    if (!qemu_cfg_port)
         // Feature not available
         return;
 
Index: seabios/src/util.h
===================================================================
--- seabios.orig/src/util.h
+++ seabios/src/util.h
@@ -264,4 +264,7 @@ extern int irq0override;
 // version (auto generated file out/version.c)
 extern const char VERSION[];
 
+// qemu-cfg.c
+extern int qemu_cfg_port;
+
 #endif // util.h

[Qemu-devel] [PATCH 3/5] Set emu_ver based on information provided by qemu_cfg.

[Jes Sorensen]

[-- Attachment #1: 0004-emulator-detect.patch --]
[-- Type: text/plain, Size: 2079 bytes --]

This patch retrieves the value of QEMU_CFG_EMULATOR and sets emu_ver,
allowing the BIOS to runtime verify which emulator it is running on.

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

---
 src/post.c     |    4 ++++
 src/qemu-cfg.c |    8 ++++++++
 src/qemu-cfg.h |    2 ++
 src/util.h     |    7 +++++++
 4 files changed, 21 insertions(+)

Index: seabios/src/post.c
===================================================================
--- seabios.orig/src/post.c
+++ seabios/src/post.c
@@ -20,6 +20,8 @@
 #include "boot.h" // IPL
 #include "qemu-cfg.h"
 
+u16 emu_ver;
+
 void
 __set_irq(int vector, void *loc)
 {
@@ -167,6 +169,8 @@ post()
      * if someone knows how to do so reliably.
      */
     qemu_cfg_port_probe();
+    if (qemu_cfg_port)
+        emu_ver = qemu_cfg_get_emulator_rev();
 
     pic_setup();
     timer_setup();
Index: seabios/src/qemu-cfg.c
===================================================================
--- seabios.orig/src/qemu-cfg.c
+++ seabios/src/qemu-cfg.c
@@ -31,3 +31,11 @@ qemu_cfg_port_probe()
     return qemu_cfg_port;
 }
 
+u16 qemu_cfg_get_emulator_rev(void)
+{
+    u16 rev;
+
+    qemu_cfg_read((u8*)&rev, QEMU_CFG_EMULATOR, sizeof(rev));
+
+    return rev;
+}
Index: seabios/src/qemu-cfg.h
===================================================================
--- seabios.orig/src/qemu-cfg.h
+++ seabios/src/qemu-cfg.h
@@ -12,8 +12,10 @@
 #define QEMU_CFG_SIGNATURE  0x00
 #define QEMU_CFG_ID         0x01
 #define QEMU_CFG_UUID       0x02
+#define QEMU_CFG_EMULATOR   0x10
 
 void qemu_cfg_read(u8 *buf, u16 f, int len);
 int qemu_cfg_port_probe();
+u16 qemu_cfg_get_emulator_rev(void);
 
 #endif
Index: seabios/src/util.h
===================================================================
--- seabios.orig/src/util.h
+++ seabios/src/util.h
@@ -267,4 +267,11 @@ extern const char VERSION[];
 // qemu-cfg.c
 extern int qemu_cfg_port;
 
+// port.c
+extern u16 emu_ver;
+#define EMU_NONE            0x0000
+#define EMU_QEMU            0x0100
+#define EMU_QEMU_KVM        0x0101
+#define EMU_QEMU_KQEMU      0x0102
+
 #endif // util.h

[Qemu-devel] [PATCH 4/5] Set irq0override based on emu_ver.

[Jes Sorensen]

[-- Attachment #1: 0005-ir0override-qemu.patch --]
[-- Type: text/plain, Size: 1000 bytes --]

Enable irq0override when we are running on QEMU. All recent versionsof
QEMU rely on irq0override, not just for KVM.

Signed-off-by: Jes Sorensen <jes@sgi.com>
---
 src/mptable.c |    4 ----
 src/post.c    |    2 ++
 2 files changed, 2 insertions(+), 4 deletions(-)

Index: seabios/src/mptable.c
===================================================================
--- seabios.orig/src/mptable.c
+++ seabios/src/mptable.c
@@ -9,11 +9,7 @@
 #include "config.h" // CONFIG_*
 #include "mptable.h" // MPTABLE_SIGNATURE
 
-#if CONFIG_KVM
-int irq0override = 1;
-#else
 int irq0override = 0;
-#endif
 
 void
 mptable_init(void)
Index: seabios/src/post.c
===================================================================
--- seabios.orig/src/post.c
+++ seabios/src/post.c
@@ -171,6 +171,8 @@ post()
     qemu_cfg_port_probe();
     if (qemu_cfg_port)
         emu_ver = qemu_cfg_get_emulator_rev();
+    if ((emu_ver & 0xff00) == EMU_QEMU)
+        irq0override = 1;
 
     pic_setup();
     timer_setup();

[Qemu-devel] [PATCH 5/5] Remove CONFIG_KVM and use emu_ver to runtime detect QEMU & KVM.

[Jes Sorensen]

[-- Attachment #1: 0006-kvm-runtime-detect.patch --]
[-- Type: text/plain, Size: 3179 bytes --]

This patch makes Seabios use emu_ver to determine QEMU and KVM
specific configuration at runtime.

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

---
 src/acpi.c    |   14 +++++++-------
 src/config.h  |    2 --
 src/pciinit.c |   18 +++++++++++++-----
 src/post.c    |    2 +-
 4 files changed, 21 insertions(+), 15 deletions(-)

Index: seabios/src/acpi.c
===================================================================
--- seabios.orig/src/acpi.c
+++ seabios/src/acpi.c
@@ -196,12 +196,8 @@ struct madt_io_apic
                                  * lines start */
 } PACKED;
 
-#if CONFIG_KVM
-/* IRQs 5,9,10,11 */
-#define PCI_ISA_IRQ_MASK    0x0e20
-#else
-#define PCI_ISA_IRQ_MASK    0x0000
-#endif
+/* IRQs 5,9,10,11 for QEMU/KQEMU/KVM */
+#define QEMU_PCI_ISA_IRQ_MASK    0x0e20
 
 struct madt_intsrcovr {
     APIC_HEADER_DEF
@@ -339,8 +335,12 @@ build_madt(struct rsdt_descriptor_rev1 *
         intsrcovr->flags  = 0; /* conforms to bus specifications */
         intsrcovr++;
     }
+    int pci_isa_irq_mask = 0;
+    if ((emu_ver & 0xff00) == EMU_QEMU)
+        pci_isa_irq_mask = QEMU_PCI_ISA_IRQ_MASK;
+
     for (i = 1; i < 16; i++) {
-        if (!(PCI_ISA_IRQ_MASK & (1 << i)))
+        if (!(pci_isa_irq_mask & (1 << i)))
             /* No need for a INT source override structure. */
             continue;
         memset(intsrcovr, 0, sizeof(*intsrcovr));
Index: seabios/src/config.h
===================================================================
--- seabios.orig/src/config.h
+++ seabios/src/config.h
@@ -12,8 +12,6 @@
 #define CONFIG_APPNAME6 "BOCHS "
 #define CONFIG_APPNAME4 "BXPC"
 
-// Configure for use with KVM.
-#define CONFIG_KVM 1
 // Configure as a coreboot payload.
 #define CONFIG_COREBOOT 0
 
Index: seabios/src/pciinit.c
===================================================================
--- seabios.orig/src/pciinit.c
+++ seabios/src/pciinit.c
@@ -18,12 +18,15 @@ static u32 pci_bios_io_addr;
 static u32 pci_bios_mem_addr;
 static u32 pci_bios_bigmem_addr;
 /* host irqs corresponding to PCI irqs A-D */
-static u8 pci_irqs[4] = {
-#if CONFIG_KVM
-    10, 10, 11, 11
-#else
+
+static u8 *pci_irqs;
+
+static u8 default_pci_irqs[4] = {
     11, 9, 11, 9
-#endif
+};
+
+static u8 qemu_pci_irqs[4] = {
+    10, 10, 11, 11
 };
 
 static void pci_set_io_region_addr(u16 bdf, int region_num, u32 addr)
@@ -194,6 +197,11 @@ pci_bios_setup(void)
         // Already done by coreboot.
         return;
 
+    if ((emu_ver & 0xff00) == EMU_QEMU)
+        pci_irqs = qemu_pci_irqs;
+    else
+        pci_irqs = default_pci_irqs;
+
     pci_bios_io_addr = 0xc000;
     pci_bios_mem_addr = 0xc0000000;
     pci_bios_bigmem_addr = RamSize;
Index: seabios/src/post.c
===================================================================
--- seabios.orig/src/post.c
+++ seabios/src/post.c
@@ -129,7 +129,7 @@ ram_probe(void)
              , E820_RESERVED);
     add_e820(BUILD_BIOS_ADDR, BUILD_BIOS_SIZE, E820_RESERVED);
 
-    if (CONFIG_KVM)
+    if (emu_ver == EMU_QEMU_KVM)
         // 4 pages before the bios, 3 pages for vmx tss pages, the
         // other page for EPT real mode pagetable
         add_e820(0xfffbc000, 4*4096, E820_RESERVED);

[Qemu-devel] Re: [PATCH 0/5] Seabios qemu detect

[Kevin O'Connor]

On Mon, Aug 03, 2009 at 03:32:36PM +0200, Jes Sorensen wrote:
> Hi,
> 
> Argh! Forgot to post this yesterday!
> 
> Here is a series of patches for Seabios which introduces support for
> QEMU_CFG_EMULATOR and uses it to select the irq0verride flag and for
> runtime detection of whether or not Seabios is running on QEMU and
> KVM.

Thanks Jes.

Once the backend work is committed to qemu or kvm, I think we should
check this into SeaBIOS.

A couple of minor notes on style: can you make the global variables
use more prominent names (eg, "EmulatorVersion" instead of "emu_ver"),
can you abstract the test "(emu_ver & 0xff00) == EMU_QEMU" into a
function - as it isn't obvious what it does, and finally, can you move
the code you added to post() into qemu_cfg_port_probe() instead?

You asked about detecting coreboot automatically.  There are several
ways to do this, but probably the easiest is to take advantage of the
fact that coreboot uses a dedicated 32bit entry point.  See the
(poorly named) post32 function in romlayout.S.

Note though, the coreboot case may still need some compile-time
checks, because of the code size increase resulting from doing the
tests at runtime.

Thanks again,
-Kevin