Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 1/6] libqos: add PPC64 PCI support

["Cédric Le Goater" <clg@kaod.org>]

On 10/03/2016 04:03 PM, Greg Kurz wrote:
> On Mon, 3 Oct 2016 13:23:27 +0200
> Cédric Le Goater <clg@kaod.org> wrote:
> 
>> On 09/29/2016 07:27 AM, David Gibson wrote:
>>> On Wed, Sep 28, 2016 at 08:51:28PM +0200, Laurent Vivier wrote:  
>>>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>>>> ---
>>>>  tests/Makefile.include   |   1 +
>>>>  tests/libqos/pci-pc.c    |  22 ----
>>>>  tests/libqos/pci-spapr.c | 280 +++++++++++++++++++++++++++++++++++++++++++++++
>>>>  tests/libqos/pci-spapr.h |  17 +++
>>>>  tests/libqos/pci.c       |  22 +++-
>>>>  tests/libqos/rtas.c      |  45 ++++++++
>>>>  tests/libqos/rtas.h      |   4 +
>>>>  7 files changed, 368 insertions(+), 23 deletions(-)
>>>>  create mode 100644 tests/libqos/pci-spapr.c
>>>>  create mode 100644 tests/libqos/pci-spapr.h
>>>>
>>>> diff --git a/tests/Makefile.include b/tests/Makefile.include
>>>> index 8162f6f..92c82d8 100644
>>>> --- a/tests/Makefile.include
>>>> +++ b/tests/Makefile.include
>>>> @@ -590,6 +590,7 @@ libqos-obj-y += tests/libqos/i2c.o tests/libqos/libqos.o
>>>>  libqos-spapr-obj-y = $(libqos-obj-y) tests/libqos/malloc-spapr.o
>>>>  libqos-spapr-obj-y += tests/libqos/libqos-spapr.o
>>>>  libqos-spapr-obj-y += tests/libqos/rtas.o
>>>> +libqos-spapr-obj-y += tests/libqos/pci-spapr.o
>>>>  libqos-pc-obj-y = $(libqos-obj-y) tests/libqos/pci-pc.o
>>>>  libqos-pc-obj-y += tests/libqos/malloc-pc.o tests/libqos/libqos-pc.o
>>>>  libqos-pc-obj-y += tests/libqos/ahci.o
>>>> diff --git a/tests/libqos/pci-pc.c b/tests/libqos/pci-pc.c
>>>> index 1ae2d37..82066b8 100644
>>>> --- a/tests/libqos/pci-pc.c
>>>> +++ b/tests/libqos/pci-pc.c
>>>> @@ -255,28 +255,6 @@ void qpci_free_pc(QPCIBus *bus)
>>>>      g_free(s);
>>>>  }
>>>>  
>>>> -void qpci_plug_device_test(const char *driver, const char *id,
>>>> -                           uint8_t slot, const char *opts)
>>>> -{
>>>> -    QDict *response;
>>>> -    char *cmd;
>>>> -
>>>> -    cmd = g_strdup_printf("{'execute': 'device_add',"
>>>> -                          " 'arguments': {"
>>>> -                          "   'driver': '%s',"
>>>> -                          "   'addr': '%d',"
>>>> -                          "   %s%s"
>>>> -                          "   'id': '%s'"
>>>> -                          "}}", driver, slot,
>>>> -                          opts ? opts : "", opts ? "," : "",
>>>> -                          id);
>>>> -    response = qmp(cmd);
>>>> -    g_free(cmd);
>>>> -    g_assert(response);
>>>> -    g_assert(!qdict_haskey(response, "error"));
>>>> -    QDECREF(response);
>>>> -}
>>>> -
>>>>  void qpci_unplug_acpi_device_test(const char *id, uint8_t slot)
>>>>  {
>>>>      QDict *response;
>>>> diff --git a/tests/libqos/pci-spapr.c b/tests/libqos/pci-spapr.c
>>>> new file mode 100644
>>>> index 0000000..78df823
>>>> --- /dev/null
>>>> +++ b/tests/libqos/pci-spapr.c
>>>> @@ -0,0 +1,280 @@
>>>> +/*
>>>> + * libqos PCI bindings for SPAPR
>>>> + *
>>>> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
>>>> + * See the COPYING file in the top-level directory.
>>>> + */
>>>> +
>>>> +#include "qemu/osdep.h"
>>>> +#include "libqtest.h"
>>>> +#include "libqos/pci-spapr.h"
>>>> +#include "libqos/rtas.h"
>>>> +
>>>> +#include "hw/pci/pci_regs.h"
>>>> +
>>>> +#include "qemu-common.h"
>>>> +#include "qemu/host-utils.h"
>>>> +
>>>> +
>>>> +/* From include/hw/pci-host/spapr.h */
>>>> +
>>>> +#define SPAPR_PCI_BASE_BUID          0x800000020000000ULL
>>>> +
>>>> +#define SPAPR_PCI_MEM_WIN_BUS_OFFSET 0x80000000ULL
>>>> +
>>>> +#define SPAPR_PCI_WINDOW_BASE        0x10000000000ULL
>>>> +#define SPAPR_PCI_WINDOW_SPACING     0x1000000000ULL
>>>> +#define SPAPR_PCI_MMIO_WIN_OFF       0xA0000000
>>>> +#define SPAPR_PCI_MMIO_WIN_SIZE      (SPAPR_PCI_WINDOW_SPACING - \
>>>> +                                     SPAPR_PCI_MEM_WIN_BUS_OFFSET)
>>>> +#define SPAPR_PCI_IO_WIN_OFF         0x80000000
>>>> +#define SPAPR_PCI_IO_WIN_SIZE        0x10000
>>>> +
>>>> +/* index is the phb index */
>>>> +
>>>> +#define BUIDBASE(index)              (SPAPR_PCI_BASE_BUID + (index))
>>>> +#define PCIBASE(index)               (SPAPR_PCI_WINDOW_BASE + \
>>>> +                                      (index) * SPAPR_PCI_WINDOW_SPACING)
>>>> +#define IOBASE(index)                (PCIBASE(index) + SPAPR_PCI_IO_WIN_OFF)
>>>> +#define MMIOBASE(index)              (PCIBASE(index) + SPAPR_PCI_MMIO_WIN_OFF)
>>>> +
>>>> +typedef struct QPCIBusSPAPR {
>>>> +    QPCIBus bus;
>>>> +    QGuestAllocator *alloc;
>>>> +
>>>> +    uint64_t pci_hole_start;
>>>> +    uint64_t pci_hole_size;
>>>> +    uint64_t pci_hole_alloc;
>>>> +
>>>> +    uint32_t pci_iohole_start;
>>>> +    uint32_t pci_iohole_size;
>>>> +    uint32_t pci_iohole_alloc;
>>>> +} QPCIBusSPAPR;
>>>> +
>>>> +static uint8_t qpci_spapr_io_readb(QPCIBus *bus, void *addr)
>>>> +{
>>>> +    uint64_t port = (uint64_t)addr;
>>>> +    uint8_t v;
>>>> +    if (port < SPAPR_PCI_IO_WIN_SIZE) {
>>>> +        v = readb(IOBASE(0) + port);
>>>> +    } else {
>>>> +        v = readb(MMIOBASE(0) + port);
>>>> +    }
>>>> +    return v;
>>>> +}
>>>> +
>>>> +static uint16_t qpci_spapr_io_readw(QPCIBus *bus, void *addr)
>>>> +{
>>>> +    uint64_t port = (uint64_t)addr;
>>>> +    uint16_t v;
>>>> +    if (port < SPAPR_PCI_IO_WIN_SIZE) {
>>>> +        v = readw(IOBASE(0) + port);
>>>> +    } else {
>>>> +        v = readw(MMIOBASE(0) + port);
>>>> +    }  
>>>
>>> Ok, so, I've looked through the qtest stuff in more detail now, and
>>> I've got a better idea of how the endianness works.  Some of my
>>> earlier comments were confused about which pieces were in the test
>>> case side and which were on the qtest accel stub side.
>>>
>>> So, what I think you need is an unconditional byteswap in each of the
>>> spapr pci IO functions.  Why?
>>>
>>>    * The plain readw() etc. functions return values read from memory
>>>      assuming guest endianness.  For guest native values in memory, so
>>>      far so good.
>>>    * Generic users of the pci read/write functions in qtest expect to
>>>      get native values.
>>>    * But PCI devices are always LE, not guest endian
>>>
>>> The guest endianness of spapr (as far as tswap() etc. are concerned)
>>> is BE, even though that's not really true in practice these days, so
>>> to correct for the PCI registers being read as BE when they should be
>>> LE we always need a swap.
>>>
>>> That should remove the need for swaps further up the test stack.
>>>
>>> Of course, "guest endianness" is a poorly defined concept, so longer
>>> term it might be better to completely replace the "readw" etc. qtest
>>> operations with explicit "readw_le" and "readw_be" ops.  
>>
>>
>> I have a similar need for a unit test of the AST2400 flash controller. 
>>
>> The flash module is accessible through a memory window and, when in 
>> SPI mode, the commands are sent to the slave by writing at the beginning 
>> of the region. Addresses are necessarily BE to be understood by the SPI
>> flash module. So, sequences like
>>
>>     writeb(AST2400_FLASH_BASE, EN_4BYTE_ADDR);
>>     writeb(AST2400_FLASH_BASE, READ);
>>     writel(AST2400_FLASH_BASE, cpu_to_be32(addr));
>>
>> will just fail under a BE host as an extra swap is done by the qtest
> 
> cpu_to_be32() is indeed what a real guest does... but the real guest runs
> with the target endianness, whereas the qtest program runs with the host
> endianness... so cpu_to_be32() looks wrong here.
> 
>> layer. I have used memwrite to have endian-agnostic mem accessors. 
>> Maybe something like below would be helpful in libqtest.h
>>
>>
>> +/*
>> + * Generic read/write helpers for a BE region
>> + */
>> +static inline void writew_be(uint64_t addr, uint16_t value)
>> +{
>> +    value = cpu_to_be16(value);
>> +    memwrite(addr, &value, sizeof(value));
>> +}
>> +
>> +static inline uint16_t readw_be(uint64_t addr)
>> +{
>> +    uint16_t value;
>> +
>> +    memread(addr, &value, sizeof(value));
>> +    return be16_to_cpu(value);
>> +}
>> +
>> +static inline void writel_be(uint64_t addr, uint32_t value)
>> +{
>> +    value = cpu_to_be32(value);
>> +    memwrite(addr, &value, sizeof(value));
>> +}
>> +
>> +static inline uint32_t readl_be(uint64_t addr)
>> +{
>> +    uint32_t value;
>> +
>> +    memread(addr, &value, sizeof(value));
>> +    return be32_to_cpu(value);
>> +}
>>
>> If this is correct, I can add the LE equivalents and send a patch.
>>
> 
> The API is correct, but the implementation has the same issue: it uses
> cpu_to_be32() and bypasses the tswap32() in qtest... the result is that
> the target endianness is totally ignored.
> 
> Let's suppose that a similar AST2400 platform exists with a BE processor:
> would the same test program work for both LE and BE cases ?
> 
> Both the test program and QEMU run with the host endianness acutally,
> but only QEMU knows about the target endianness. So I guess, the qtest
> protocol should provide explicit BE/LE operations: the test program
> would ask for an access with a specific endianness and the qtest
> accelerator in QEMU would do the swap based on the target endianness.

Here is a RFC below, tested on a BE and LE host for a BE region.

Thanks,
C. 


From: Cédric Le Goater <clg@kaod.org>
Subject: [PATCH] qtest: add an endianness parameter to read/write accessors
Date: Mon, 03 Oct 2016 16:52:48 +0200
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This adds {read,write}{w,l,q}_{be,le} routines to access guest memory
using a specific endianness. The protocol is simply extented to pass
"be", "le", "native".

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 qtest.c          |   73 +++++++++++++++++++++++++++++++++++++++++-----
 tests/libqtest.c |   86 +++++++++++++++++++++++++++++++++++++++++++++++--------
 tests/libqtest.h |   68 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 207 insertions(+), 20 deletions(-)

Index: qemu-aspeed.git/tests/libqtest.h
===================================================================
--- qemu-aspeed.git.orig/tests/libqtest.h
+++ qemu-aspeed.git/tests/libqtest.h
@@ -888,4 +888,72 @@ void qmp_fd_send(int fd, const char *fmt
 QDict *qmp_fdv(int fd, const char *fmt, va_list ap);
 QDict *qmp_fd(int fd, const char *fmt, ...);
 
+uint16_t qtest_readw_be(QTestState *s, uint64_t addr);
+uint32_t qtest_readl_be(QTestState *s, uint64_t addr);
+uint64_t qtest_readq_be(QTestState *s, uint64_t addr);
+
+static inline uint16_t readw_be(uint64_t addr)
+{
+    return qtest_readw_be(global_qtest, addr);
+}
+static inline uint32_t readl_be(uint64_t addr)
+{
+    return qtest_readl_be(global_qtest, addr);
+}
+static inline uint64_t readq_be(uint64_t addr)
+{
+    return qtest_readq_be(global_qtest, addr);
+}
+
+void qtest_writew_be(QTestState *s, uint64_t addr, uint16_t value);
+void qtest_writel_be(QTestState *s, uint64_t addr, uint32_t value);
+void qtest_writeq_be(QTestState *s, uint64_t addr, uint64_t value);
+
+static inline void writew_be(uint64_t addr, uint16_t value)
+{
+    qtest_writew_be(global_qtest, addr, value);
+}
+static inline void writel_be(uint64_t addr, uint32_t value)
+{
+    qtest_writel_be(global_qtest, addr, value);
+}
+static inline void writeq_be(uint64_t addr, uint64_t value)
+{
+    qtest_writeq_be(global_qtest, addr, value);
+}
+
+uint16_t qtest_readw_le(QTestState *s, uint64_t addr);
+uint32_t qtest_readl_le(QTestState *s, uint64_t addr);
+uint64_t qtest_readq_le(QTestState *s, uint64_t addr);
+
+static inline uint16_t readw_le(uint64_t addr)
+{
+    return qtest_readw_le(global_qtest, addr);
+}
+static inline uint32_t readl_le(uint64_t addr)
+{
+    return qtest_readl_le(global_qtest, addr);
+}
+static inline uint64_t readq_le(uint64_t addr)
+{
+    return qtest_readq_le(global_qtest, addr);
+}
+
+void qtest_writew_le(QTestState *s, uint64_t addr, uint16_t value);
+void qtest_writel_le(QTestState *s, uint64_t addr, uint32_t value);
+void qtest_writeq_le(QTestState *s, uint64_t addr, uint64_t value);
+
+static inline void writew_le(uint64_t addr, uint16_t value)
+{
+    qtest_writew_le(global_qtest, addr, value);
+}
+static inline void writel_le(uint64_t addr, uint32_t value)
+{
+    qtest_writel_le(global_qtest, addr, value);
+}
+static inline void writeq_le(uint64_t addr, uint64_t value)
+{
+    qtest_writeq_le(global_qtest, addr, value);
+}
+
 #endif
Index: qemu-aspeed.git/qtest.c
===================================================================
--- qemu-aspeed.git.orig/qtest.c
+++ qemu-aspeed.git/qtest.c
@@ -257,6 +257,63 @@ static void qtest_irq_handler(void *opaq
     }
 }
 
+static inline bool is_target_big_endian(void)
+{
+#if defined(TARGET_WORDS_BIGENDIAN)
+    return true;
+#else
+    return false;
+#endif
+}
+
+static void qtest_tswap16s(uint16_t *s, gchar *endianness)
+{
+    if (endianness[0] != 'n') {
+        bool big_endian = (endianness[0] == 'b');
+
+        if (is_target_big_endian() != big_endian) {
+            bswap16s(s);
+        }
+    }
+    tswap16s(s);
+}
+
+static uint16_t qtest_tswap16(uint16_t s, gchar *endianness)
+{
+    qtest_tswap16s(&s, endianness);
+    return s;
+}
+
+static void qtest_tswap32s(uint32_t *s, gchar *endianness)
+{
+    if (endianness[0] != 'n') {
+        bool big_endian = (endianness[0] == 'b');
+
+        if (is_target_big_endian() != big_endian) {
+            bswap32s(s);
+        }
+    }
+    tswap32s(s);
+}
+
+static uint32_t qtest_tswap32(uint32_t s, gchar *endianness)
+{
+    qtest_tswap32s(&s, endianness);
+    return s;
+}
+
+static void qtest_tswap64s(uint64_t *s, gchar *endianness)
+{
+    if (endianness[0] != 'n') {
+        bool big_endian = (endianness[0] == 'b');
+
+        if (is_target_big_endian() != big_endian) {
+            bswap64s(s);
+        }
+    }
+    tswap64s(s);
+}
+
 static void qtest_process_command(CharDriverState *chr, gchar **words)
 {
     const gchar *command;
@@ -372,7 +429,7 @@ static void qtest_process_command(CharDr
         uint64_t addr;
         uint64_t value;
 
-        g_assert(words[1] && words[2]);
+        g_assert(words[1] && words[2] && words[3]);
         g_assert(qemu_strtoull(words[1], NULL, 0, &addr) == 0);
         g_assert(qemu_strtoull(words[2], NULL, 0, &value) == 0);
 
@@ -381,15 +438,15 @@ static void qtest_process_command(CharDr
             cpu_physical_memory_write(addr, &data, 1);
         } else if (words[0][5] == 'w') {
             uint16_t data = value;
-            tswap16s(&data);
+            qtest_tswap16s(&data, words[3]);
             cpu_physical_memory_write(addr, &data, 2);
         } else if (words[0][5] == 'l') {
             uint32_t data = value;
-            tswap32s(&data);
+            qtest_tswap32s(&data, words[3]);
             cpu_physical_memory_write(addr, &data, 4);
         } else if (words[0][5] == 'q') {
             uint64_t data = value;
-            tswap64s(&data);
+            qtest_tswap64s(&data, words[3]);
             cpu_physical_memory_write(addr, &data, 8);
         }
         qtest_send_prefix(chr);
@@ -401,7 +458,7 @@ static void qtest_process_command(CharDr
         uint64_t addr;
         uint64_t value = UINT64_C(-1);
 
-        g_assert(words[1]);
+        g_assert(words[1] && words[2]);
         g_assert(qemu_strtoull(words[1], NULL, 0, &addr) == 0);
 
         if (words[0][4] == 'b') {
@@ -411,14 +468,14 @@ static void qtest_process_command(CharDr
         } else if (words[0][4] == 'w') {
             uint16_t data;
             cpu_physical_memory_read(addr, &data, 2);
-            value = tswap16(data);
+            value = qtest_tswap16(data, words[2]);
         } else if (words[0][4] == 'l') {
             uint32_t data;
             cpu_physical_memory_read(addr, &data, 4);
-            value = tswap32(data);
+            value = qtest_tswap32(data, words[2]);
         } else if (words[0][4] == 'q') {
             cpu_physical_memory_read(addr, &value, 8);
-            tswap64s(&value);
+            qtest_tswap64s(&value, words[2]);
         }
         qtest_send_prefix(chr);
         qtest_sendf(chr, "OK 0x%016" PRIx64 "\n", value);
Index: qemu-aspeed.git/tests/libqtest.c
===================================================================
--- qemu-aspeed.git.orig/tests/libqtest.c
+++ qemu-aspeed.git/tests/libqtest.c
@@ -663,38 +663,70 @@ uint32_t qtest_inl(QTestState *s, uint16
 }
 
 static void qtest_write(QTestState *s, const char *cmd, uint64_t addr,
-                        uint64_t value)
+                        uint64_t value, const char *endianness)
 {
-    qtest_sendf(s, "%s 0x%" PRIx64 " 0x%" PRIx64 "\n", cmd, addr, value);
+    qtest_sendf(s, "%s 0x%" PRIx64 " 0x%" PRIx64  " %s\n", cmd, addr, value,
+                endianness);
     qtest_rsp(s, 0);
 }
 
 void qtest_writeb(QTestState *s, uint64_t addr, uint8_t value)
 {
-    qtest_write(s, "writeb", addr, value);
+    qtest_write(s, "writeb", addr, value, "native");
 }
 
 void qtest_writew(QTestState *s, uint64_t addr, uint16_t value)
 {
-    qtest_write(s, "writew", addr, value);
+    qtest_write(s, "writew", addr, value, "native");
 }
 
 void qtest_writel(QTestState *s, uint64_t addr, uint32_t value)
 {
-    qtest_write(s, "writel", addr, value);
+    qtest_write(s, "writel", addr, value, "native");
 }
 
 void qtest_writeq(QTestState *s, uint64_t addr, uint64_t value)
 {
-    qtest_write(s, "writeq", addr, value);
+    qtest_write(s, "writeq", addr, value, "native");
 }
 
-static uint64_t qtest_read(QTestState *s, const char *cmd, uint64_t addr)
+void qtest_writew_be(QTestState *s, uint64_t addr, uint16_t value)
+{
+    qtest_write(s, "writew", addr, value, "be");
+}
+
+void qtest_writel_be(QTestState *s, uint64_t addr, uint32_t value)
+{
+    qtest_write(s, "writel", addr, value, "be");
+}
+
+void qtest_writeq_be(QTestState *s, uint64_t addr, uint64_t value)
+{
+    qtest_write(s, "writeq", addr, value, "be");
+}
+
+void qtest_writew_le(QTestState *s, uint64_t addr, uint16_t value)
+{
+    qtest_write(s, "writew", addr, value, "le");
+}
+
+void qtest_writel_le(QTestState *s, uint64_t addr, uint32_t value)
+{
+    qtest_write(s, "writel", addr, value, "le");
+}
+
+void qtest_writeq_le(QTestState *s, uint64_t addr, uint64_t value)
+{
+    qtest_write(s, "writeq", addr, value, "le");
+}
+
+static uint64_t qtest_read(QTestState *s, const char *cmd, uint64_t addr,
+                           const char *endianness)
 {
     gchar **args;
     uint64_t value;
 
-    qtest_sendf(s, "%s 0x%" PRIx64 "\n", cmd, addr);
+    qtest_sendf(s, "%s 0x%" PRIx64 " %s\n", cmd, addr, endianness);
     args = qtest_rsp(s, 2);
     value = strtoull(args[1], NULL, 0);
     g_strfreev(args);
@@ -704,22 +736,52 @@ static uint64_t qtest_read(QTestState *s
 
 uint8_t qtest_readb(QTestState *s, uint64_t addr)
 {
-    return qtest_read(s, "readb", addr);
+    return qtest_read(s, "readb", addr, "native");
 }
 
 uint16_t qtest_readw(QTestState *s, uint64_t addr)
 {
-    return qtest_read(s, "readw", addr);
+    return qtest_read(s, "readw", addr, "native");
 }
 
 uint32_t qtest_readl(QTestState *s, uint64_t addr)
 {
-    return qtest_read(s, "readl", addr);
+    return qtest_read(s, "readl", addr, "native");
 }
 
 uint64_t qtest_readq(QTestState *s, uint64_t addr)
 {
-    return qtest_read(s, "readq", addr);
+    return qtest_read(s, "readq", addr, "native");
+}
+
+uint16_t qtest_readw_be(QTestState *s, uint64_t addr)
+{
+    return qtest_read(s, "readw", addr, "be");
+}
+
+uint32_t qtest_readl_be(QTestState *s, uint64_t addr)
+{
+    return qtest_read(s, "readl", addr, "be");
+}
+
+uint64_t qtest_readq_be(QTestState *s, uint64_t addr)
+{
+    return qtest_read(s, "readq", addr, "be");
+}
+
+uint16_t qtest_readw_le(QTestState *s, uint64_t addr)
+{
+    return qtest_read(s, "readw", addr, "le");
+}
+
+uint32_t qtest_readl_le(QTestState *s, uint64_t addr)
+{
+    return qtest_read(s, "readl", addr, "le");
+}
+
+uint64_t qtest_readq_le(QTestState *s, uint64_t addr)
+{
+    return qtest_read(s, "readq", addr, "le");
 }
 
 static int hex2nib(char ch)