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* [PATCH v2 0/3] multiboot: Use DMA instead port-based transfer
@ 2021-10-20 14:02 Paolo Bonzini
  2021-10-20 14:02 ` [PATCH 1/3] target/i386: move linuxboot_dma_enabled to X86MachineState Paolo Bonzini
                   ` (3 more replies)
  0 siblings, 4 replies; 8+ messages in thread
From: Paolo Bonzini @ 2021-10-20 14:02 UTC (permalink / raw)
  To: qemu-devel; +Cc: adam, marcus.haehnel

An updated version of the patch at
https://patchew.org/QEMU/YWM6jboU9fUib6Iy@os.inf.tu-dresden.de/,
which includes the necessary glue for compatibility with older
machine types.  When fw_cfg DMA is disabled, the existing ROM
is used instead.

Marcus Hähnel (1):
  optionrom: add a DMA-enabled multiboot ROM

Paolo Bonzini (2):
  target/i386: move linuxboot_dma_enabled to X86MachineState
  target/i386: use DMA-enabled multiboot ROM for new-enough QEMU machine
    types

 hw/i386/microvm.c                 |   5 ++-
 hw/i386/multiboot.c               |  10 ++++-
 hw/i386/multiboot.h               |   4 +-
 hw/i386/pc.c                      |   8 ++--
 hw/i386/pc_piix.c                 |   3 +-
 hw/i386/pc_q35.c                  |   3 +-
 hw/i386/x86.c                     |   7 ++--
 include/hw/i386/pc.h              |   3 --
 include/hw/i386/x86.h             |   5 ++-
 pc-bios/meson.build               |   1 +
 pc-bios/multiboot_dma.bin         | Bin 0 -> 1024 bytes
 pc-bios/optionrom/Makefile        |   4 +-
 pc-bios/optionrom/multiboot.S     |   4 +-
 pc-bios/optionrom/multiboot_dma.S |   2 +
 pc-bios/optionrom/optionrom.h     |  66 ++++++++++++++++++++++++++++++
 15 files changed, 102 insertions(+), 23 deletions(-)
 create mode 100644 pc-bios/multiboot_dma.bin
 create mode 100644 pc-bios/optionrom/multiboot_dma.S

-- 
2.31.1



^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH 1/3] target/i386: move linuxboot_dma_enabled to X86MachineState
  2021-10-20 14:02 [PATCH v2 0/3] multiboot: Use DMA instead port-based transfer Paolo Bonzini
@ 2021-10-20 14:02 ` Paolo Bonzini
  2021-10-20 19:13   ` Philippe Mathieu-Daudé
  2021-10-20 14:02 ` [PATCH 2/3] optionrom: add a DMA-enabled multiboot ROM Paolo Bonzini
                   ` (2 subsequent siblings)
  3 siblings, 1 reply; 8+ messages in thread
From: Paolo Bonzini @ 2021-10-20 14:02 UTC (permalink / raw)
  To: qemu-devel; +Cc: adam, marcus.haehnel

This removes a parameter from x86_load_linux, and will avoid code
duplication between the linux and multiboot cases once multiboot
starts to support DMA.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/i386/microvm.c     | 5 ++++-
 hw/i386/pc.c          | 5 ++---
 hw/i386/pc_piix.c     | 3 ++-
 hw/i386/pc_q35.c      | 3 ++-
 hw/i386/x86.c         | 5 +++--
 include/hw/i386/pc.h  | 3 ---
 include/hw/i386/x86.h | 5 +++--
 7 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index f257ec5a0b..837bafb64a 100644
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -331,7 +331,7 @@ static void microvm_memory_init(MicrovmMachineState *mms)
     rom_set_fw(fw_cfg);
 
     if (machine->kernel_filename != NULL) {
-        x86_load_linux(x86ms, fw_cfg, 0, true, true);
+        x86_load_linux(x86ms, fw_cfg, 0, true);
     }
 
     if (mms->option_roms) {
@@ -667,6 +667,7 @@ static void microvm_machine_initfn(Object *obj)
 
 static void microvm_class_init(ObjectClass *oc, void *data)
 {
+    X86MachineClass *x86mc = X86_MACHINE_CLASS(oc);
     MachineClass *mc = MACHINE_CLASS(oc);
     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
 
@@ -697,6 +698,8 @@ static void microvm_class_init(ObjectClass *oc, void *data)
     hc->unplug_request = microvm_device_unplug_request_cb;
     hc->unplug = microvm_device_unplug_cb;
 
+    x86mc->fwcfg_dma_enabled = true;
+
     object_class_property_add(oc, MICROVM_MACHINE_PIC, "OnOffAuto",
                               microvm_machine_get_pic,
                               microvm_machine_set_pic,
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 86223acfd3..d203db7845 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -775,7 +775,7 @@ void xen_load_linux(PCMachineState *pcms)
     rom_set_fw(fw_cfg);
 
     x86_load_linux(x86ms, fw_cfg, pcmc->acpi_data_size,
-                   pcmc->pvh_enabled, pcmc->linuxboot_dma_enabled);
+                   pcmc->pvh_enabled);
     for (i = 0; i < nb_option_roms; i++) {
         assert(!strcmp(option_rom[i].name, "linuxboot.bin") ||
                !strcmp(option_rom[i].name, "linuxboot_dma.bin") ||
@@ -927,7 +927,7 @@ void pc_memory_init(PCMachineState *pcms,
 
     if (linux_boot) {
         x86_load_linux(x86ms, fw_cfg, pcmc->acpi_data_size,
-                       pcmc->pvh_enabled, pcmc->linuxboot_dma_enabled);
+                       pcmc->pvh_enabled);
     }
 
     for (i = 0; i < nb_option_roms; i++) {
@@ -1664,7 +1664,6 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
     /* BIOS ACPI tables: 128K. Other BIOS datastructures: less than 4K reported
      * to be used at the moment, 32K should be enough for a while.  */
     pcmc->acpi_data_size = 0x20000 + 0x8000;
-    pcmc->linuxboot_dma_enabled = true;
     pcmc->pvh_enabled = true;
     pcmc->kvmclock_create_always = true;
     assert(!mc->get_hotplug_handler);
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 6ad0d763c5..223dd3e05d 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -620,11 +620,12 @@ DEFINE_I440FX_MACHINE(v2_7, "pc-i440fx-2.7", NULL,
 
 static void pc_i440fx_2_6_machine_options(MachineClass *m)
 {
+    X86MachineClass *x86mc = X86_MACHINE_CLASS(m);
     PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
 
     pc_i440fx_2_7_machine_options(m);
     pcmc->legacy_cpu_hotplug = true;
-    pcmc->linuxboot_dma_enabled = false;
+    x86mc->fwcfg_dma_enabled = false;
     compat_props_add(m->compat_props, hw_compat_2_6, hw_compat_2_6_len);
     compat_props_add(m->compat_props, pc_compat_2_6, pc_compat_2_6_len);
 }
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index fcc6e4eb2b..797e09500b 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -573,11 +573,12 @@ DEFINE_Q35_MACHINE(v2_7, "pc-q35-2.7", NULL,
 
 static void pc_q35_2_6_machine_options(MachineClass *m)
 {
+    X86MachineClass *x86mc = X86_MACHINE_CLASS(m);
     PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
 
     pc_q35_2_7_machine_options(m);
     pcmc->legacy_cpu_hotplug = true;
-    pcmc->linuxboot_dma_enabled = false;
+    x86mc->fwcfg_dma_enabled = false;
     compat_props_add(m->compat_props, hw_compat_2_6, hw_compat_2_6_len);
     compat_props_add(m->compat_props, pc_compat_2_6, pc_compat_2_6_len);
 }
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 76de7e2265..a34498fe16 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -764,9 +764,9 @@ static bool load_elfboot(const char *kernel_filename,
 void x86_load_linux(X86MachineState *x86ms,
                     FWCfgState *fw_cfg,
                     int acpi_data_size,
-                    bool pvh_enabled,
-                    bool linuxboot_dma_enabled)
+                    bool pvh_enabled)
 {
+    bool linuxboot_dma_enabled = X86_MACHINE_GET_CLASS(x86ms)->fwcfg_dma_enabled;
     uint16_t protocol;
     int setup_size, kernel_size, cmdline_size;
     int dtb_size, setup_data_offset;
@@ -1332,6 +1332,7 @@ static void x86_machine_class_init(ObjectClass *oc, void *data)
     mc->possible_cpu_arch_ids = x86_possible_cpu_arch_ids;
     x86mc->compat_apic_id_mode = false;
     x86mc->save_tsc_khz = true;
+    x86mc->fwcfg_dma_enabled = true;
     nc->nmi_monitor_handler = x86_nmi;
 
     object_class_property_add(oc, X86_MACHINE_SMM, "OnOffAuto",
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 11426e26dc..9162aded21 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -116,9 +116,6 @@ struct PCMachineClass {
     /* generate legacy CPU hotplug AML */
     bool legacy_cpu_hotplug;
 
-    /* use DMA capable linuxboot option rom */
-    bool linuxboot_dma_enabled;
-
     /* use PVH to load kernels that support this feature */
     bool pvh_enabled;
 
diff --git a/include/hw/i386/x86.h b/include/hw/i386/x86.h
index 23267a3674..bb1cfb8896 100644
--- a/include/hw/i386/x86.h
+++ b/include/hw/i386/x86.h
@@ -38,6 +38,8 @@ struct X86MachineClass {
     bool save_tsc_khz;
     /* Enables contiguous-apic-ID mode */
     bool compat_apic_id_mode;
+    /* use DMA capable linuxboot option rom */
+    bool fwcfg_dma_enabled;
 };
 
 struct X86MachineState {
@@ -120,8 +122,7 @@ void x86_bios_rom_init(MachineState *ms, const char *default_firmware,
 void x86_load_linux(X86MachineState *x86ms,
                     FWCfgState *fw_cfg,
                     int acpi_data_size,
-                    bool pvh_enabled,
-                    bool linuxboot_dma_enabled);
+                    bool pvh_enabled);
 
 bool x86_machine_is_smm_enabled(const X86MachineState *x86ms);
 bool x86_machine_is_acpi_enabled(const X86MachineState *x86ms);
-- 
2.31.1




^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH 2/3] optionrom: add a DMA-enabled multiboot ROM
  2021-10-20 14:02 [PATCH v2 0/3] multiboot: Use DMA instead port-based transfer Paolo Bonzini
  2021-10-20 14:02 ` [PATCH 1/3] target/i386: move linuxboot_dma_enabled to X86MachineState Paolo Bonzini
@ 2021-10-20 14:02 ` Paolo Bonzini
  2021-10-20 22:08   ` Philippe Mathieu-Daudé
  2021-10-20 14:02 ` [PATCH 3/3] target/i386: use DMA-enabled multiboot ROM for new-enough QEMU machine types Paolo Bonzini
  2021-10-21  7:23 ` [PATCH v2 0/3] multiboot: Use DMA instead port-based transfer Stefano Garzarella
  3 siblings, 1 reply; 8+ messages in thread
From: Paolo Bonzini @ 2021-10-20 14:02 UTC (permalink / raw)
  To: qemu-devel; +Cc: adam, marcus.haehnel

From: Marcus Hähnel <marcus.haehnel@kernkonzept.com>

Add a new option rom for the multiboot loader, using DMA transfers to copy
data instead of "rep insb".

This significantly lowers QEMU's startup latency by a factor of about 40,
for example, going from 30sec to 0.8sec when loading modules of 120MB
in size.

Signed-off-by: Marcus Hähnel <marcus.haehnel@kernkonzept.com>
Signed-off-by: Adam Lackorzynski <adam@l4re.org>
[Modified to keep the non-DMA code depending on #ifdef USE_FW_CFG_DMA;
 do not write below stack. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 pc-bios/meson.build               |   1 +
 pc-bios/multiboot_dma.bin         | Bin 0 -> 1024 bytes
 pc-bios/optionrom/Makefile        |   4 +-
 pc-bios/optionrom/multiboot.S     |   4 +-
 pc-bios/optionrom/multiboot_dma.S |   2 +
 pc-bios/optionrom/optionrom.h     |  66 ++++++++++++++++++++++++++++++
 6 files changed, 72 insertions(+), 5 deletions(-)
 create mode 100644 pc-bios/multiboot_dma.bin
 create mode 100644 pc-bios/optionrom/multiboot_dma.S

diff --git a/pc-bios/meson.build b/pc-bios/meson.build
index a44c9bc127..b40ff3f2bd 100644
--- a/pc-bios/meson.build
+++ b/pc-bios/meson.build
@@ -63,6 +63,7 @@ blobs = files(
   'petalogix-s3adsp1800.dtb',
   'petalogix-ml605.dtb',
   'multiboot.bin',
+  'multiboot_dma.bin',
   'linuxboot.bin',
   'linuxboot_dma.bin',
   'kvmvapic.bin',
diff --git a/pc-bios/multiboot_dma.bin b/pc-bios/multiboot_dma.bin
new file mode 100644
index 0000000000000000000000000000000000000000..c0e2c3102a3358207c61d3ae113524fb6007abc3
GIT binary patch
literal 1024
zcmd^-v1=1i9LIlmUTlcNU1}{N5`u&{DAHSmq6iKdix;GHRxaNnR0A<Lc978Fk#IvN
zaS+5wQE+fL&*iQWa#czc94ZyL>R{3q;@~8~^LMo;4s!p158nI!-tWur_ul*P<{!&%
z=%3>xm5f`4Bq!!)`Rkwf;(oFd*qcAb=mhXX1)X>Bw-tylkUpR_ETXkH1AnO4L$nJ|
zWJui_M1kmKmTID)P`mI^=HM`~{VB1t1l_Ye=Lor4X5{8Gd)zzw_o4<6zLQJ!dr<pW
z;7%~ysSHL?*HHx*O%k}?fCyRL<7_RWt(4;Aqn}X}S>MolrKNZG2Z|kTOyaJIhYFc^
zFhhuQ9`r5fQLCrm#T4^_QylQ>8kgs;ZX9bIEiXb`8AIxu;?h~d%9izBkKht%WM1G*
z^E{W9(OT9dt5in2qF}|dPH>dL>{=sV#-U1<quUb@YkIW%niI?8-7fCz#695e<V=WZ
zrVCY?W~`3Hw@^=cHALr#9F2GOTYJ;??9d*-Vbsi+;lz|<$jMX#;lr6ov3qKNLH7(W
z+>yFoWnOtw14D$&k*SUtsT%wS`ki@#&rUrnmtuDv`PtJm(Kg?H$Pdc0CL@YCy4R<D
pT|LnIbg(BnP0#tqRx5M!bkkaD-nd?`H;YU4Yi6yHwD{k({tHC8FAx9#

literal 0
HcmV?d00001

diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile
index 3482508a86..5d55d25acc 100644
--- a/pc-bios/optionrom/Makefile
+++ b/pc-bios/optionrom/Makefile
@@ -2,7 +2,7 @@ include config.mak
 SRC_DIR := $(TOPSRC_DIR)/pc-bios/optionrom
 VPATH = $(SRC_DIR)
 
-all: multiboot.bin linuxboot.bin linuxboot_dma.bin kvmvapic.bin pvh.bin
+all: multiboot.bin multiboot_dma.bin linuxboot.bin linuxboot_dma.bin kvmvapic.bin pvh.bin
 # Dummy command so that make thinks it has done something
 	@true
 
@@ -41,8 +41,6 @@ override CFLAGS += $(call cc-option, $(Wa)-32)
 LD_I386_EMULATION ?= elf_i386
 override LDFLAGS = -m $(LD_I386_EMULATION) -T $(SRC_DIR)/flat.lds
 
-all: multiboot.bin linuxboot.bin linuxboot_dma.bin kvmvapic.bin pvh.bin
-
 pvh.img: pvh.o pvh_main.o
 
 %.o: %.S
diff --git a/pc-bios/optionrom/multiboot.S b/pc-bios/optionrom/multiboot.S
index b7efe4de34..181a4b03a3 100644
--- a/pc-bios/optionrom/multiboot.S
+++ b/pc-bios/optionrom/multiboot.S
@@ -68,7 +68,7 @@ run_multiboot:
 	mov		%eax, %es
 
 	/* Read the bootinfo struct into RAM */
-	read_fw_blob(FW_CFG_INITRD)
+	read_fw_blob_dma(FW_CFG_INITRD)
 
 	/* FS = bootinfo_struct */
 	read_fw		FW_CFG_INITRD_ADDR
@@ -188,7 +188,7 @@ prot_mode:
 	movl		%eax, %gs
 
 	/* Read the kernel and modules into RAM */
-	read_fw_blob(FW_CFG_KERNEL)
+	read_fw_blob_dma(FW_CFG_KERNEL)
 
 	/* Jump off to the kernel */
 	read_fw		FW_CFG_KERNEL_ENTRY
diff --git a/pc-bios/optionrom/multiboot_dma.S b/pc-bios/optionrom/multiboot_dma.S
new file mode 100644
index 0000000000..d809af3e23
--- /dev/null
+++ b/pc-bios/optionrom/multiboot_dma.S
@@ -0,0 +1,2 @@
+#define USE_FW_CFG_DMA 1
+#include "multiboot.S"
diff --git a/pc-bios/optionrom/optionrom.h b/pc-bios/optionrom/optionrom.h
index a2b612f1a7..8d74c0ddf3 100644
--- a/pc-bios/optionrom/optionrom.h
+++ b/pc-bios/optionrom/optionrom.h
@@ -37,6 +37,17 @@
 #define BIOS_CFG_IOPORT_CFG	0x510
 #define BIOS_CFG_IOPORT_DATA	0x511
 
+#define FW_CFG_DMA_CTL_ERROR   0x01
+#define FW_CFG_DMA_CTL_READ    0x02
+#define FW_CFG_DMA_CTL_SKIP    0x04
+#define FW_CFG_DMA_CTL_SELECT  0x08
+#define FW_CFG_DMA_CTL_WRITE   0x10
+
+#define FW_CFG_DMA_SIGNATURE 0x51454d5520434647ULL /* "QEMU CFG" */
+
+#define BIOS_CFG_DMA_ADDR_HIGH  0x514
+#define BIOS_CFG_DMA_ADDR_LOW   0x518
+
 /* Break the translation block flow so -d cpu shows us values */
 #define DEBUG_HERE \
 	jmp		1f;				\
@@ -62,6 +73,61 @@
 	bswap		%eax
 .endm
 
+
+/*
+ * Read data from the fw_cfg device using DMA.
+ * Clobbers:	%edx, %eax, ADDR, SIZE, memory[%esp-16] to memory[%esp]
+ */
+.macro read_fw_dma VAR, SIZE, ADDR
+        /* Address */
+	bswapl		\ADDR
+	pushl		\ADDR
+
+	/* We only support 32 bit target addresses */
+	xorl		%eax, %eax
+	pushl		%eax
+	mov		$BIOS_CFG_DMA_ADDR_HIGH, %dx
+	outl		%eax, (%dx)
+
+	/* Size */
+	bswapl		\SIZE
+	pushl		\SIZE
+
+        /* Control */
+	movl		$(\VAR << 16) | (FW_CFG_DMA_CTL_READ | FW_CFG_DMA_CTL_SELECT), %eax
+	bswapl		%eax
+	pushl		%eax
+
+	movl		%esp, %eax /* Address of the struct we generated */
+	bswapl		%eax
+	mov		$BIOS_CFG_DMA_ADDR_LOW, %dx
+	outl		%eax, (%dx) /* Initiate DMA */
+
+1:  mov		(%esp), %eax /* Wait for completion */
+	bswapl		%eax
+	testl		$~FW_CFG_DMA_CTL_ERROR, %eax
+	jnz		1b
+       addl            $16, %esp
+.endm
+
+
+/*
+ * Read a blob from the fw_cfg device using DMA
+ * Requires _ADDR, _SIZE and _DATA values for the parameter.
+ *
+ * Clobbers:	%eax, %edx, %es, %ecx, %edi and adresses %esp-20 to %esp
+ */
+#ifdef USE_FW_CFG_DMA
+#define read_fw_blob_dma(var) \
+	read_fw		var ## _SIZE; \
+	mov		%eax, %ecx; \
+	read_fw		var ## _ADDR; \
+	mov		%eax, %edi ;\
+	read_fw_dma	var ## _DATA, %ecx, %edi
+#else
+#define read_fw_blob_dma(var) read_fw_blob(var)
+#endif
+
 #define read_fw_blob_pre(var)				\
 	read_fw		var ## _SIZE;			\
 	mov		%eax, %ecx;			\
-- 
2.31.1




^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH 3/3] target/i386: use DMA-enabled multiboot ROM for new-enough QEMU machine types
  2021-10-20 14:02 [PATCH v2 0/3] multiboot: Use DMA instead port-based transfer Paolo Bonzini
  2021-10-20 14:02 ` [PATCH 1/3] target/i386: move linuxboot_dma_enabled to X86MachineState Paolo Bonzini
  2021-10-20 14:02 ` [PATCH 2/3] optionrom: add a DMA-enabled multiboot ROM Paolo Bonzini
@ 2021-10-20 14:02 ` Paolo Bonzini
  2021-10-20 19:19   ` Philippe Mathieu-Daudé
  2021-10-21  7:23 ` [PATCH v2 0/3] multiboot: Use DMA instead port-based transfer Stefano Garzarella
  3 siblings, 1 reply; 8+ messages in thread
From: Paolo Bonzini @ 2021-10-20 14:02 UTC (permalink / raw)
  To: qemu-devel; +Cc: adam, marcus.haehnel

As long as fw_cfg supports DMA, the new ROM can be used also on older
machine types because it has the same size as the existing one.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/i386/multiboot.c | 10 ++++++++--
 hw/i386/multiboot.h |  4 +++-
 hw/i386/pc.c        |  3 ++-
 hw/i386/x86.c       |  2 +-
 4 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c
index 9e7d69d470..0a10089f14 100644
--- a/hw/i386/multiboot.c
+++ b/hw/i386/multiboot.c
@@ -143,7 +143,8 @@ static void mb_add_mod(MultibootState *s,
     s->mb_mods_count++;
 }
 
-int load_multiboot(FWCfgState *fw_cfg,
+int load_multiboot(X86MachineState *x86ms,
+                   FWCfgState *fw_cfg,
                    FILE *f,
                    const char *kernel_filename,
                    const char *initrd_filename,
@@ -151,6 +152,7 @@ int load_multiboot(FWCfgState *fw_cfg,
                    int kernel_file_size,
                    uint8_t *header)
 {
+    bool multiboot_dma_enabled = X86_MACHINE_GET_CLASS(x86ms)->fwcfg_dma_enabled;
     int i, is_multiboot = 0;
     uint32_t flags = 0;
     uint32_t mh_entry_addr;
@@ -401,7 +403,11 @@ int load_multiboot(FWCfgState *fw_cfg,
     fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
                      sizeof(bootinfo));
 
-    option_rom[nb_option_roms].name = "multiboot.bin";
+    if (multiboot_dma_enabled) {
+        option_rom[nb_option_roms].name = "multiboot_dma.bin";
+    } else {
+        option_rom[nb_option_roms].name = "multiboot.bin";
+    }
     option_rom[nb_option_roms].bootindex = 0;
     nb_option_roms++;
 
diff --git a/hw/i386/multiboot.h b/hw/i386/multiboot.h
index 60de309cd1..2b9182a8ea 100644
--- a/hw/i386/multiboot.h
+++ b/hw/i386/multiboot.h
@@ -2,8 +2,10 @@
 #define QEMU_MULTIBOOT_H
 
 #include "hw/nvram/fw_cfg.h"
+#include "hw/i386/x86.h"
 
-int load_multiboot(FWCfgState *fw_cfg,
+int load_multiboot(X86MachineState *x86ms,
+                   FWCfgState *fw_cfg,
                    FILE *f,
                    const char *kernel_filename,
                    const char *initrd_filename,
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index d203db7845..fcfb7f7139 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -780,7 +780,8 @@ void xen_load_linux(PCMachineState *pcms)
         assert(!strcmp(option_rom[i].name, "linuxboot.bin") ||
                !strcmp(option_rom[i].name, "linuxboot_dma.bin") ||
                !strcmp(option_rom[i].name, "pvh.bin") ||
-               !strcmp(option_rom[i].name, "multiboot.bin"));
+               !strcmp(option_rom[i].name, "multiboot.bin") ||
+               !strcmp(option_rom[i].name, "multiboot_dma.bin"));
         rom_add_option(option_rom[i].name, option_rom[i].bootindex);
     }
     x86ms->fw_cfg = fw_cfg;
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index a34498fe16..b84840a1bb 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -814,7 +814,7 @@ void x86_load_linux(X86MachineState *x86ms,
          * PVH), so we try multiboot first since we check the multiboot magic
          * header before to load it.
          */
-        if (load_multiboot(fw_cfg, f, kernel_filename, initrd_filename,
+        if (load_multiboot(x86ms, fw_cfg, f, kernel_filename, initrd_filename,
                            kernel_cmdline, kernel_size, header)) {
             return;
         }
-- 
2.31.1



^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH 1/3] target/i386: move linuxboot_dma_enabled to X86MachineState
  2021-10-20 14:02 ` [PATCH 1/3] target/i386: move linuxboot_dma_enabled to X86MachineState Paolo Bonzini
@ 2021-10-20 19:13   ` Philippe Mathieu-Daudé
  0 siblings, 0 replies; 8+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-10-20 19:13 UTC (permalink / raw)
  To: Paolo Bonzini, qemu-devel; +Cc: adam, marcus.haehnel

On 10/20/21 16:02, Paolo Bonzini wrote:
> This removes a parameter from x86_load_linux, and will avoid code
> duplication between the linux and multiboot cases once multiboot
> starts to support DMA.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  hw/i386/microvm.c     | 5 ++++-
>  hw/i386/pc.c          | 5 ++---
>  hw/i386/pc_piix.c     | 3 ++-
>  hw/i386/pc_q35.c      | 3 ++-
>  hw/i386/x86.c         | 5 +++--
>  include/hw/i386/pc.h  | 3 ---
>  include/hw/i386/x86.h | 5 +++--
>  7 files changed, 16 insertions(+), 13 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>



^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH 3/3] target/i386: use DMA-enabled multiboot ROM for new-enough QEMU machine types
  2021-10-20 14:02 ` [PATCH 3/3] target/i386: use DMA-enabled multiboot ROM for new-enough QEMU machine types Paolo Bonzini
@ 2021-10-20 19:19   ` Philippe Mathieu-Daudé
  0 siblings, 0 replies; 8+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-10-20 19:19 UTC (permalink / raw)
  To: Paolo Bonzini, qemu-devel; +Cc: adam, marcus.haehnel

On 10/20/21 16:02, Paolo Bonzini wrote:
> As long as fw_cfg supports DMA, the new ROM can be used also on older
> machine types because it has the same size as the existing one.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  hw/i386/multiboot.c | 10 ++++++++--
>  hw/i386/multiboot.h |  4 +++-
>  hw/i386/pc.c        |  3 ++-
>  hw/i386/x86.c       |  2 +-
>  4 files changed, 14 insertions(+), 5 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>



^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH 2/3] optionrom: add a DMA-enabled multiboot ROM
  2021-10-20 14:02 ` [PATCH 2/3] optionrom: add a DMA-enabled multiboot ROM Paolo Bonzini
@ 2021-10-20 22:08   ` Philippe Mathieu-Daudé
  0 siblings, 0 replies; 8+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-10-20 22:08 UTC (permalink / raw)
  To: Paolo Bonzini, qemu-devel; +Cc: adam, marcus.haehnel

On 10/20/21 16:02, Paolo Bonzini wrote:
> From: Marcus Hähnel <marcus.haehnel@kernkonzept.com>
> 
> Add a new option rom for the multiboot loader, using DMA transfers to copy
> data instead of "rep insb".
> 
> This significantly lowers QEMU's startup latency by a factor of about 40,
> for example, going from 30sec to 0.8sec when loading modules of 120MB
> in size.
> 
> Signed-off-by: Marcus Hähnel <marcus.haehnel@kernkonzept.com>
> Signed-off-by: Adam Lackorzynski <adam@l4re.org>
> [Modified to keep the non-DMA code depending on #ifdef USE_FW_CFG_DMA;
>  do not write below stack. - Paolo]
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  pc-bios/meson.build               |   1 +
>  pc-bios/multiboot_dma.bin         | Bin 0 -> 1024 bytes
>  pc-bios/optionrom/Makefile        |   4 +-
>  pc-bios/optionrom/multiboot.S     |   4 +-
>  pc-bios/optionrom/multiboot_dma.S |   2 +
>  pc-bios/optionrom/optionrom.h     |  66 ++++++++++++++++++++++++++++++
>  6 files changed, 72 insertions(+), 5 deletions(-)
>  create mode 100644 pc-bios/multiboot_dma.bin
>  create mode 100644 pc-bios/optionrom/multiboot_dma.S

> diff --git a/pc-bios/multiboot_dma.bin b/pc-bios/multiboot_dma.bin
> new file mode 100644
> index 0000000000000000000000000000000000000000..c0e2c3102a3358207c61d3ae113524fb6007abc3
> GIT binary patch
> literal 1024
> zcmd^-v1=1i9LIlmUTlcNU1}{N5`u&{DAHSmq6iKdix;GHRxaNnR0A<Lc978Fk#IvN
> zaS+5wQE+fL&*iQWa#czc94ZyL>R{3q;@~8~^LMo;4s!p158nI!-tWur_ul*P<{!&%
> z=%3>xm5f`4Bq!!)`Rkwf;(oFd*qcAb=mhXX1)X>Bw-tylkUpR_ETXkH1AnO4L$nJ|
> zWJui_M1kmKmTID)P`mI^=HM`~{VB1t1l_Ye=Lor4X5{8Gd)zzw_o4<6zLQJ!dr<pW
> z;7%~ysSHL?*HHx*O%k}?fCyRL<7_RWt(4;Aqn}X}S>MolrKNZG2Z|kTOyaJIhYFc^
> zFhhuQ9`r5fQLCrm#T4^_QylQ>8kgs;ZX9bIEiXb`8AIxu;?h~d%9izBkKht%WM1G*
> z^E{W9(OT9dt5in2qF}|dPH>dL>{=sV#-U1<quUb@YkIW%niI?8-7fCz#695e<V=WZ
> zrVCY?W~`3Hw@^=cHALr#9F2GOTYJ;??9d*-Vbsi+;lz|<$jMX#;lr6ov3qKNLH7(W
> z+>yFoWnOtw14D$&k*SUtsT%wS`ki@#&rUrnmtuDv`PtJm(Kg?H$Pdc0CL@YCy4R<D
> pT|LnIbg(BnP0#tqRx5M!bkkaD-nd?`H;YU4Yi6yHwD{k({tHC8FAx9#

Ideally this should be generated on CI as artifact, archived
and we commit the CI generated file.

> diff --git a/pc-bios/optionrom/optionrom.h b/pc-bios/optionrom/optionrom.h
> index a2b612f1a7..8d74c0ddf3 100644
> --- a/pc-bios/optionrom/optionrom.h
> +++ b/pc-bios/optionrom/optionrom.h
> @@ -37,6 +37,17 @@
>  #define BIOS_CFG_IOPORT_CFG	0x510
>  #define BIOS_CFG_IOPORT_DATA	0x511
>  
> +#define FW_CFG_DMA_CTL_ERROR   0x01
> +#define FW_CFG_DMA_CTL_READ    0x02
> +#define FW_CFG_DMA_CTL_SKIP    0x04
> +#define FW_CFG_DMA_CTL_SELECT  0x08
> +#define FW_CFG_DMA_CTL_WRITE   0x10
> +
> +#define FW_CFG_DMA_SIGNATURE 0x51454d5520434647ULL /* "QEMU CFG" */
> +
> +#define BIOS_CFG_DMA_ADDR_HIGH  0x514
> +#define BIOS_CFG_DMA_ADDR_LOW   0x518
> +
>  /* Break the translation block flow so -d cpu shows us values */
>  #define DEBUG_HERE \
>  	jmp		1f;				\
> @@ -62,6 +73,61 @@
>  	bswap		%eax
>  .endm
>  
> +
> +/*
> + * Read data from the fw_cfg device using DMA.
> + * Clobbers:	%edx, %eax, ADDR, SIZE, memory[%esp-16] to memory[%esp]
> + */
> +.macro read_fw_dma VAR, SIZE, ADDR
> +        /* Address */
> +	bswapl		\ADDR
> +	pushl		\ADDR
> +
> +	/* We only support 32 bit target addresses */
> +	xorl		%eax, %eax
> +	pushl		%eax
> +	mov		$BIOS_CFG_DMA_ADDR_HIGH, %dx
> +	outl		%eax, (%dx)
> +
> +	/* Size */
> +	bswapl		\SIZE
> +	pushl		\SIZE
> +
> +        /* Control */

Indent off.

> +	movl		$(\VAR << 16) | (FW_CFG_DMA_CTL_READ | FW_CFG_DMA_CTL_SELECT), %eax
> +	bswapl		%eax
> +	pushl		%eax
> +
> +	movl		%esp, %eax /* Address of the struct we generated */
> +	bswapl		%eax
> +	mov		$BIOS_CFG_DMA_ADDR_LOW, %dx
> +	outl		%eax, (%dx) /* Initiate DMA */
> +
> +1:  mov		(%esp), %eax /* Wait for completion */
> +	bswapl		%eax
> +	testl		$~FW_CFG_DMA_CTL_ERROR, %eax
> +	jnz		1b
> +       addl            $16, %esp

Indent off.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>



^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v2 0/3] multiboot: Use DMA instead port-based transfer
  2021-10-20 14:02 [PATCH v2 0/3] multiboot: Use DMA instead port-based transfer Paolo Bonzini
                   ` (2 preceding siblings ...)
  2021-10-20 14:02 ` [PATCH 3/3] target/i386: use DMA-enabled multiboot ROM for new-enough QEMU machine types Paolo Bonzini
@ 2021-10-21  7:23 ` Stefano Garzarella
  3 siblings, 0 replies; 8+ messages in thread
From: Stefano Garzarella @ 2021-10-21  7:23 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: adam, qemu-devel, marcus.haehnel

On Wed, Oct 20, 2021 at 04:02:41PM +0200, Paolo Bonzini wrote:
>An updated version of the patch at
>https://patchew.org/QEMU/YWM6jboU9fUib6Iy@os.inf.tu-dresden.de/,
>which includes the necessary glue for compatibility with older
>machine types.  When fw_cfg DMA is disabled, the existing ROM
>is used instead.
>
>Marcus Hähnel (1):
>  optionrom: add a DMA-enabled multiboot ROM
>
>Paolo Bonzini (2):
>  target/i386: move linuxboot_dma_enabled to X86MachineState
>  target/i386: use DMA-enabled multiboot ROM for new-enough QEMU machine
>    types
>
> hw/i386/microvm.c                 |   5 ++-
> hw/i386/multiboot.c               |  10 ++++-
> hw/i386/multiboot.h               |   4 +-
> hw/i386/pc.c                      |   8 ++--
> hw/i386/pc_piix.c                 |   3 +-
> hw/i386/pc_q35.c                  |   3 +-
> hw/i386/x86.c                     |   7 ++--
> include/hw/i386/pc.h              |   3 --
> include/hw/i386/x86.h             |   5 ++-
> pc-bios/meson.build               |   1 +
> pc-bios/multiboot_dma.bin         | Bin 0 -> 1024 bytes
> pc-bios/optionrom/Makefile        |   4 +-
> pc-bios/optionrom/multiboot.S     |   4 +-
> pc-bios/optionrom/multiboot_dma.S |   2 +
> pc-bios/optionrom/optionrom.h     |  66 ++++++++++++++++++++++++++++++
> 15 files changed, 102 insertions(+), 23 deletions(-)
> create mode 100644 pc-bios/multiboot_dma.bin
> create mode 100644 pc-bios/optionrom/multiboot_dma.S
>
>-- 
>2.31.1
>
>

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>



^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2021-10-21  7:24 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-10-20 14:02 [PATCH v2 0/3] multiboot: Use DMA instead port-based transfer Paolo Bonzini
2021-10-20 14:02 ` [PATCH 1/3] target/i386: move linuxboot_dma_enabled to X86MachineState Paolo Bonzini
2021-10-20 19:13   ` Philippe Mathieu-Daudé
2021-10-20 14:02 ` [PATCH 2/3] optionrom: add a DMA-enabled multiboot ROM Paolo Bonzini
2021-10-20 22:08   ` Philippe Mathieu-Daudé
2021-10-20 14:02 ` [PATCH 3/3] target/i386: use DMA-enabled multiboot ROM for new-enough QEMU machine types Paolo Bonzini
2021-10-20 19:19   ` Philippe Mathieu-Daudé
2021-10-21  7:23 ` [PATCH v2 0/3] multiboot: Use DMA instead port-based transfer Stefano Garzarella

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