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* [PATCH] RFC: simplify kvm-userspace to qemu-kvm callback structure
@ 2007-12-05 14:52 Christian Ehrhardt
       [not found] ` <4756BB14.1080708-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
  0 siblings, 1 reply; 6+ messages in thread
From: Christian Ehrhardt @ 2007-12-05 14:52 UTC (permalink / raw)
  To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
	Hollis Blanchard, kvm-ppc-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
	Jerone Young

[-- Attachment #1: Type: text/plain, Size: 7652 bytes --]

Background:
In our ppc code for the demo we only needed a call to cpu_physical_memory_rw to handle all kind of mmio we needed. Looking at all the callback pointers for read/write mmio in kvm_callbacks I wondered if this can be simplified with cpu_physical_memory_rw for x86 too. So I tested it today and it works fine on with kvm-svm on my opteron.
The only code that did not just redirect to another function was a workaround for a Redhat 7.1 issue, so I merged it in the central call making it easier to find and maintain (was split before) anyway.
If everyone agrees with it I will create a new patch also affecting the other implementations of this interface e.g. user/main.c and a rebased version of this one.
But maybe there was a reason to do it that split way with all the callback pointers that was not obvious to me, so please comment.

P.S. up to now I did not find such a single function in qemu to handle the normal I/O (non mm), but maybe there is more potential to slimline that callback stuff.

---

Subject: [PATCH] simplify kvm-userspace to qemu-kvm callback structure

From: Christian Ehrhardt <ehrhardt-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>

Merging the kvm callback elements write[bwlq] and read[bwlq] into a single call
simplifying that interface.
Additionally this patch fixes a small typo and combines two workarounds for the
same issue in code the patch touches anyway.

Signed-off-by: Christian Ehrhardt <ehrhardt-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
---

[diffstat]
 libkvm/libkvm.c |   40 ++++--------------------------------
 libkvm/libkvm.h |   19 ++---------------
 qemu/qemu-kvm.c |   62 +++-----------------------------------------------------
 3 files changed, 12 insertions(+), 109 deletions(-)

[diff (also attached)]
diff --git a/libkvm/libkvm.c b/libkvm/libkvm.c
index 573a9ab..057706c 100644
--- a/libkvm/libkvm.c
+++ b/libkvm/libkvm.c
@@ -771,44 +771,14 @@ static int handle_mmio(kvm_context_t kvm, struct kvm_run *kvm_run)
 {
 	unsigned long addr = kvm_run->mmio.phys_addr;
 	void *data = kvm_run->mmio.data;
-	int r = -1;
 
-	/* hack: Red Hat 7.1 generates these wierd accesses. */
-	if (addr == 0xa0000 && kvm_run->mmio.len == 3)
+	/* hack: Red Hat 7.1 generates these weird accesses. */
+	if ((addr > 0xa0000-4 && addr <= 0xa0000) && kvm_run->mmio.len == 3)
 	    return 0;
 
-	if (kvm_run->mmio.is_write) {
-		switch (kvm_run->mmio.len) {
-		case 1:
-			r = kvm->callbacks->writeb(kvm->opaque, addr, *(uint8_t *)data);
-			break;
-		case 2:
-			r = kvm->callbacks->writew(kvm->opaque, addr, *(uint16_t *)data);
-			break;
-		case 4:
-			r = kvm->callbacks->writel(kvm->opaque, addr, *(uint32_t *)data);
-			break;
-		case 8:
-			r = kvm->callbacks->writeq(kvm->opaque, addr, *(uint64_t *)data);
-			break;
-		}
-	} else {
-		switch (kvm_run->mmio.len) {
-		case 1:
-			r = kvm->callbacks->readb(kvm->opaque, addr, (uint8_t *)data);
-			break;
-		case 2:
-			r = kvm->callbacks->readw(kvm->opaque, addr, (uint16_t *)data);
-			break;
-		case 4:
-			r = kvm->callbacks->readl(kvm->opaque, addr, (uint32_t *)data);
-			break;
-		case 8:
-			r = kvm->callbacks->readq(kvm->opaque, addr, (uint64_t *)data);
-			break;
-		}
-	}
-	return r;
+	return kvm->callbacks->mmio_rw(kvm->opaque, addr, data,
+					kvm_run->mmio.len,
+					kvm_run->mmio.is_write);
 }
 
 int handle_io_window(kvm_context_t kvm)
diff --git a/libkvm/libkvm.h b/libkvm/libkvm.h
index ff260f4..d44a364 100644
--- a/libkvm/libkvm.h
+++ b/libkvm/libkvm.h
@@ -45,22 +45,9 @@ struct kvm_callbacks {
     int (*outw)(void *opaque, uint16_t addr, uint16_t data);
 	/// For 32bit IO writes from the guest (Usually when executing 'outl')
     int (*outl)(void *opaque, uint16_t addr, uint32_t data);
-	/// For 8bit memory reads from unmapped memory (For MMIO devices)
-    int (*readb)(void *opaque, uint64_t addr, uint8_t *data);
-	/// For 16bit memory reads from unmapped memory (For MMIO devices)
-    int (*readw)(void *opaque, uint64_t addr, uint16_t *data);
-	/// For 32bit memory reads from unmapped memory (For MMIO devices)
-    int (*readl)(void *opaque, uint64_t addr, uint32_t *data);
-	/// For 64bit memory reads from unmapped memory (For MMIO devices)
-    int (*readq)(void *opaque, uint64_t addr, uint64_t *data);
-	/// For 8bit memory writes to unmapped memory (For MMIO devices)
-    int (*writeb)(void *opaque, uint64_t addr, uint8_t data);
-	/// For 16bit memory writes to unmapped memory (For MMIO devices)
-    int (*writew)(void *opaque, uint64_t addr, uint16_t data);
-	/// For 32bit memory writes to unmapped memory (For MMIO devices)
-    int (*writel)(void *opaque, uint64_t addr, uint32_t data);
-	/// For 64bit memory writes to unmapped memory (For MMIO devices)
-    int (*writeq)(void *opaque, uint64_t addr, uint64_t data);
+	/// generic memory writes to unmapped memory (For MMIO devices)
+    int (*mmio_rw)(void *opaque, uint64_t addr, uint8_t *data,
+					int len, int is_write);
     int (*debug)(void *opaque, int vcpu);
 	/*!
 	 * \brief Called when the VCPU issues an 'hlt' instruction.
diff --git a/qemu/qemu-kvm.c b/qemu/qemu-kvm.c
index 3aeba39..2b61a42 100644
--- a/qemu/qemu-kvm.c
+++ b/qemu/qemu-kvm.c
@@ -477,58 +477,11 @@ static int kvm_outl(void *opaque, uint16_t addr, uint32_t data)
     return 0;
 }
 
-static int kvm_readb(void *opaque, uint64_t addr, uint8_t *data)
+static int kvm_mmio_rw(void *opaque, uint64_t addr,
+					uint8_t *data, int len, int is_write)
 {
-    *data = ldub_phys(addr);
-    return 0;
-}
- 
-static int kvm_readw(void *opaque, uint64_t addr, uint16_t *data)
-{
-    *data = lduw_phys(addr);
-    return 0;
-}
-
-static int kvm_readl(void *opaque, uint64_t addr, uint32_t *data)
-{
-    /* hack: Red Hat 7.1 generates some wierd accesses. */
-    if (addr > 0xa0000 - 4 && addr < 0xa0000) {
-	*data = 0;
+	cpu_physical_memory_rw(addr,data,len,is_write);
 	return 0;
-    }
-
-    *data = ldl_phys(addr);
-    return 0;
-}
-
-static int kvm_readq(void *opaque, uint64_t addr, uint64_t *data)
-{
-    *data = ldq_phys(addr);
-    return 0;
-}
-
-static int kvm_writeb(void *opaque, uint64_t addr, uint8_t data)
-{
-    stb_phys(addr, data);
-    return 0;
-}
-
-static int kvm_writew(void *opaque, uint64_t addr, uint16_t data)
-{
-    stw_phys(addr, data);
-    return 0;
-}
-
-static int kvm_writel(void *opaque, uint64_t addr, uint32_t data)
-{
-    stl_phys(addr, data);
-    return 0;
-}
-
-static int kvm_writeq(void *opaque, uint64_t addr, uint64_t data)
-{
-    stq_phys(addr, data);
-    return 0;
 }
 
 static int kvm_io_window(void *opaque)
@@ -556,14 +509,7 @@ static struct kvm_callbacks qemu_kvm_ops = {
     .outb  = kvm_outb,
     .outw  = kvm_outw,
     .outl  = kvm_outl,
-    .readb = kvm_readb,
-    .readw = kvm_readw,
-    .readl = kvm_readl,
-    .readq = kvm_readq,
-    .writeb = kvm_writeb,
-    .writew = kvm_writew,
-    .writel = kvm_writel,
-    .writeq = kvm_writeq,
+    .mmio_rw = kvm_mmio_rw,
     .halt  = kvm_halt,
     .shutdown = kvm_shutdown,
     .io_window = kvm_io_window,



-- 

Grüsse / regards, 
Christian Ehrhardt

IBM Linux Technology Center, Open Virtualization
+49 7031/16-3385
Ehrhardt-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org
Ehrhardt-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org

IBM Deutschland Entwicklung GmbH
Vorsitzender des Aufsichtsrats: Johann Weihen 
Geschäftsführung: Herbert Kircher 
Sitz der Gesellschaft: Böblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294

[-- Attachment #2: simplify_kvm_callback --]
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diff --git a/libkvm/libkvm.c b/libkvm/libkvm.c
index 573a9ab..057706c 100644
--- a/libkvm/libkvm.c
+++ b/libkvm/libkvm.c
@@ -771,44 +771,14 @@ static int handle_mmio(kvm_context_t kvm, struct kvm_run *kvm_run)
 {
 	unsigned long addr = kvm_run->mmio.phys_addr;
 	void *data = kvm_run->mmio.data;
-	int r = -1;
 
-	/* hack: Red Hat 7.1 generates these wierd accesses. */
-	if (addr == 0xa0000 && kvm_run->mmio.len == 3)
+	/* hack: Red Hat 7.1 generates these weird accesses. */
+	if ((addr > 0xa0000-4 && addr <= 0xa0000) && kvm_run->mmio.len == 3)
 	    return 0;
 
-	if (kvm_run->mmio.is_write) {
-		switch (kvm_run->mmio.len) {
-		case 1:
-			r = kvm->callbacks->writeb(kvm->opaque, addr, *(uint8_t *)data);
-			break;
-		case 2:
-			r = kvm->callbacks->writew(kvm->opaque, addr, *(uint16_t *)data);
-			break;
-		case 4:
-			r = kvm->callbacks->writel(kvm->opaque, addr, *(uint32_t *)data);
-			break;
-		case 8:
-			r = kvm->callbacks->writeq(kvm->opaque, addr, *(uint64_t *)data);
-			break;
-		}
-	} else {
-		switch (kvm_run->mmio.len) {
-		case 1:
-			r = kvm->callbacks->readb(kvm->opaque, addr, (uint8_t *)data);
-			break;
-		case 2:
-			r = kvm->callbacks->readw(kvm->opaque, addr, (uint16_t *)data);
-			break;
-		case 4:
-			r = kvm->callbacks->readl(kvm->opaque, addr, (uint32_t *)data);
-			break;
-		case 8:
-			r = kvm->callbacks->readq(kvm->opaque, addr, (uint64_t *)data);
-			break;
-		}
-	}
-	return r;
+	return kvm->callbacks->mmio_rw(kvm->opaque, addr, data,
+					kvm_run->mmio.len,
+					kvm_run->mmio.is_write);
 }
 
 int handle_io_window(kvm_context_t kvm)
diff --git a/libkvm/libkvm.h b/libkvm/libkvm.h
index ff260f4..d44a364 100644
--- a/libkvm/libkvm.h
+++ b/libkvm/libkvm.h
@@ -45,22 +45,9 @@ struct kvm_callbacks {
     int (*outw)(void *opaque, uint16_t addr, uint16_t data);
 	/// For 32bit IO writes from the guest (Usually when executing 'outl')
     int (*outl)(void *opaque, uint16_t addr, uint32_t data);
-	/// For 8bit memory reads from unmapped memory (For MMIO devices)
-    int (*readb)(void *opaque, uint64_t addr, uint8_t *data);
-	/// For 16bit memory reads from unmapped memory (For MMIO devices)
-    int (*readw)(void *opaque, uint64_t addr, uint16_t *data);
-	/// For 32bit memory reads from unmapped memory (For MMIO devices)
-    int (*readl)(void *opaque, uint64_t addr, uint32_t *data);
-	/// For 64bit memory reads from unmapped memory (For MMIO devices)
-    int (*readq)(void *opaque, uint64_t addr, uint64_t *data);
-	/// For 8bit memory writes to unmapped memory (For MMIO devices)
-    int (*writeb)(void *opaque, uint64_t addr, uint8_t data);
-	/// For 16bit memory writes to unmapped memory (For MMIO devices)
-    int (*writew)(void *opaque, uint64_t addr, uint16_t data);
-	/// For 32bit memory writes to unmapped memory (For MMIO devices)
-    int (*writel)(void *opaque, uint64_t addr, uint32_t data);
-	/// For 64bit memory writes to unmapped memory (For MMIO devices)
-    int (*writeq)(void *opaque, uint64_t addr, uint64_t data);
+	/// generic memory writes to unmapped memory (For MMIO devices)
+    int (*mmio_rw)(void *opaque, uint64_t addr, uint8_t *data,
+					int len, int is_write);
     int (*debug)(void *opaque, int vcpu);
 	/*!
 	 * \brief Called when the VCPU issues an 'hlt' instruction.
diff --git a/qemu/qemu-kvm.c b/qemu/qemu-kvm.c
index 3aeba39..2b61a42 100644
--- a/qemu/qemu-kvm.c
+++ b/qemu/qemu-kvm.c
@@ -477,58 +477,11 @@ static int kvm_outl(void *opaque, uint16_t addr, uint32_t data)
     return 0;
 }
 
-static int kvm_readb(void *opaque, uint64_t addr, uint8_t *data)
+static int kvm_mmio_rw(void *opaque, uint64_t addr,
+					uint8_t *data, int len, int is_write)
 {
-    *data = ldub_phys(addr);
-    return 0;
-}
- 
-static int kvm_readw(void *opaque, uint64_t addr, uint16_t *data)
-{
-    *data = lduw_phys(addr);
-    return 0;
-}
-
-static int kvm_readl(void *opaque, uint64_t addr, uint32_t *data)
-{
-    /* hack: Red Hat 7.1 generates some wierd accesses. */
-    if (addr > 0xa0000 - 4 && addr < 0xa0000) {
-	*data = 0;
+	cpu_physical_memory_rw(addr,data,len,is_write);
 	return 0;
-    }
-
-    *data = ldl_phys(addr);
-    return 0;
-}
-
-static int kvm_readq(void *opaque, uint64_t addr, uint64_t *data)
-{
-    *data = ldq_phys(addr);
-    return 0;
-}
-
-static int kvm_writeb(void *opaque, uint64_t addr, uint8_t data)
-{
-    stb_phys(addr, data);
-    return 0;
-}
-
-static int kvm_writew(void *opaque, uint64_t addr, uint16_t data)
-{
-    stw_phys(addr, data);
-    return 0;
-}
-
-static int kvm_writel(void *opaque, uint64_t addr, uint32_t data)
-{
-    stl_phys(addr, data);
-    return 0;
-}
-
-static int kvm_writeq(void *opaque, uint64_t addr, uint64_t data)
-{
-    stq_phys(addr, data);
-    return 0;
 }
 
 static int kvm_io_window(void *opaque)
@@ -556,14 +509,7 @@ static struct kvm_callbacks qemu_kvm_ops = {
     .outb  = kvm_outb,
     .outw  = kvm_outw,
     .outl  = kvm_outl,
-    .readb = kvm_readb,
-    .readw = kvm_readw,
-    .readl = kvm_readl,
-    .readq = kvm_readq,
-    .writeb = kvm_writeb,
-    .writew = kvm_writew,
-    .writel = kvm_writel,
-    .writeq = kvm_writeq,
+    .mmio_rw = kvm_mmio_rw,
     .halt  = kvm_halt,
     .shutdown = kvm_shutdown,
     .io_window = kvm_io_window,

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^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2007-12-11 13:01 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2007-12-05 14:52 [PATCH] RFC: simplify kvm-userspace to qemu-kvm callback structure Christian Ehrhardt
     [not found] ` <4756BB14.1080708-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2007-12-06 14:50   ` Avi Kivity
     [not found]     ` <47580C1B.4090708-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-12-11 13:01       ` Christian Ehrhardt
2007-12-07 11:38   ` [PATCH] [0/1] " Christian Ehrhardt
     [not found]     ` <475930A6.60301-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2007-12-07 11:40       ` Avi Kivity
2007-12-07 11:38   ` [PATCH] [1/1] " Christian Ehrhardt

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