From: Paul Durrant <paul.durrant@citrix.com>
To: xen-devel@lists.xenproject.org
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
Paul Durrant <paul.durrant@citrix.com>,
Keir Fraser <keir@xen.org>, Jan Beulich <jbeulich@suse.com>
Subject: [PATCH v2 17/17] x86/hvm: track large memory mapped accesses by buffer offset
Date: Thu, 11 Jun 2015 16:43:01 +0100 [thread overview]
Message-ID: <1434037381-10917-18-git-send-email-paul.durrant@citrix.com> (raw)
In-Reply-To: <1434037381-10917-1-git-send-email-paul.durrant@citrix.com>
The code in hvmemul_do_io() that tracks large reads or writes, to avoid
re-issue of component I/O, is defeated by accesses across a page boundary
because it uses physical address. The code is also only relevant to memory
mapped I/O to or from a buffer.
This patch re-factors the code and moves it into hvmemul_phys_mmio_access()
where it is relevant and tracks using buffer offset rather then address.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Keir Fraser <keir@xen.org>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
---
xen/arch/x86/hvm/emulate.c | 86 ++++++++++++++--------------------------
xen/include/asm-x86/hvm/vcpu.h | 16 ++++----
2 files changed, 39 insertions(+), 63 deletions(-)
diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index 467f2da..867498f 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -109,29 +109,6 @@ static int hvmemul_do_io(
return X86EMUL_UNHANDLEABLE;
}
- if ( is_mmio && !data_is_addr )
- {
- /* Part of a multi-cycle read or write? */
- if ( dir == IOREQ_WRITE )
- {
- paddr_t pa = vio->mmio_large_write_pa;
- unsigned int bytes = vio->mmio_large_write_bytes;
- if ( (addr >= pa) && ((addr + size) <= (pa + bytes)) )
- return X86EMUL_OKAY;
- }
- else
- {
- paddr_t pa = vio->mmio_large_read_pa;
- unsigned int bytes = vio->mmio_large_read_bytes;
- if ( (addr >= pa) && ((addr + size) <= (pa + bytes)) )
- {
- memcpy(p_data, &vio->mmio_large_read[addr - pa],
- size);
- return X86EMUL_OKAY;
- }
- }
- }
-
switch ( vio->io_req.state )
{
case STATE_IOREQ_NONE:
@@ -165,34 +142,6 @@ static int hvmemul_do_io(
memcpy(p_data, &p.data, size);
}
- if ( is_mmio && !data_is_addr )
- {
- /* Part of a multi-cycle read or write? */
- if ( dir == IOREQ_WRITE )
- {
- paddr_t pa = vio->mmio_large_write_pa;
- unsigned int bytes = vio->mmio_large_write_bytes;
- if ( bytes == 0 )
- pa = vio->mmio_large_write_pa = addr;
- if ( addr == (pa + bytes) )
- vio->mmio_large_write_bytes += size;
- }
- else
- {
- paddr_t pa = vio->mmio_large_read_pa;
- unsigned int bytes = vio->mmio_large_read_bytes;
- if ( bytes == 0 )
- pa = vio->mmio_large_read_pa = addr;
- if ( (addr == (pa + bytes)) &&
- ((bytes + size) <= sizeof(vio->mmio_large_read)) )
- {
- memcpy(&vio->mmio_large_read[addr - pa], p_data,
- size);
- vio->mmio_large_read_bytes += size;
- }
- }
- }
-
*reps = p.count;
return X86EMUL_OKAY;
default:
@@ -625,6 +574,7 @@ static int hvmemul_phys_mmio_access(paddr_t gpa,
uint8_t *buffer,
unsigned int *off)
{
+ struct hvm_vcpu_io *vio = ¤t->arch.hvm_vcpu.hvm_io;
unsigned long one_rep = 1;
unsigned int chunk;
int rc = 0;
@@ -644,10 +594,34 @@ static int hvmemul_phys_mmio_access(paddr_t gpa,
while ( size != 0 )
{
- rc = hvmemul_do_mmio_buffer(gpa, &one_rep, chunk, dir, 0,
- &buffer[*off]);
- if ( rc != X86EMUL_OKAY )
- break;
+ /* Have we already done this chunk? */
+ if ( (*off + chunk) <= vio->mmio_cache[dir].size )
+ {
+ ASSERT(*off + chunk <= vio->mmio_cache[dir].size);
+
+ if ( dir == IOREQ_READ )
+ memcpy(&buffer[*off],
+ &vio->mmio_cache[IOREQ_READ].buffer[*off],
+ chunk);
+ else
+ ASSERT(memcmp(&buffer[*off],
+ &vio->mmio_cache[IOREQ_WRITE].buffer[*off],
+ chunk) == 0);
+ }
+ else
+ {
+ ASSERT(*off == vio->mmio_cache[dir].size);
+
+ rc = hvmemul_do_mmio_buffer(gpa, &one_rep, chunk, dir, 0,
+ &buffer[*off]);
+ if ( rc != X86EMUL_OKAY )
+ break;
+
+ /* Note that we have now done this chunk */
+ memcpy(&vio->mmio_cache[dir].buffer[*off],
+ &buffer[*off], chunk);
+ vio->mmio_cache[dir].size += chunk;
+ }
/* Advance to the next chunk */
gpa += chunk;
@@ -1675,7 +1649,7 @@ static int _hvm_emulate_one(struct hvm_emulate_ctxt *hvmemul_ctxt,
rc = X86EMUL_RETRY;
if ( rc != X86EMUL_RETRY )
{
- vio->mmio_large_read_bytes = vio->mmio_large_write_bytes = 0;
+ memset(&vio->mmio_cache, 0, sizeof(vio->mmio_cache));
vio->mmio_insn_bytes = 0;
}
else
diff --git a/xen/include/asm-x86/hvm/vcpu.h b/xen/include/asm-x86/hvm/vcpu.h
index 46e89e4..261b649 100644
--- a/xen/include/asm-x86/hvm/vcpu.h
+++ b/xen/include/asm-x86/hvm/vcpu.h
@@ -56,13 +56,15 @@ struct hvm_vcpu_io {
unsigned long mmio_gva;
unsigned long mmio_gpfn;
- /* We may read up to m256 as a number of device-model transactions. */
- paddr_t mmio_large_read_pa;
- uint8_t mmio_large_read[32];
- unsigned int mmio_large_read_bytes;
- /* We may write up to m256 as a number of device-model transactions. */
- unsigned int mmio_large_write_bytes;
- paddr_t mmio_large_write_pa;
+ /*
+ * We may read or write up to m256 as a number of device-model
+ * transactions.
+ */
+ struct {
+ unsigned long size;
+ uint8_t buffer[32];
+ } mmio_cache[2]; /* Indexed by ioreq type */
+
/* For retries we shouldn't re-fetch the instruction. */
unsigned int mmio_insn_bytes;
unsigned char mmio_insn[16];
--
1.7.10.4
next prev parent reply other threads:[~2015-06-11 15:51 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-11 15:42 [PATCH v2 00/17] x86/hvm: I/O emulation cleanup and fix Paul Durrant
2015-06-11 15:42 ` [PATCH v2 01/17] x86/hvm: simplify hvmemul_do_io() Paul Durrant
2015-06-17 13:31 ` Jan Beulich
2015-06-17 13:54 ` Paul Durrant
2015-06-17 14:47 ` Jan Beulich
2015-06-17 14:55 ` Paul Durrant
2015-06-17 14:59 ` Jan Beulich
2015-06-11 15:42 ` [PATCH v2 02/17] x86/hvm: re-name struct hvm_mmio_handler to hvm_mmio_ops Paul Durrant
2015-06-17 12:43 ` Jan Beulich
2015-06-17 12:45 ` Paul Durrant
2015-06-11 15:42 ` [PATCH v2 03/17] x86/hvm: unify internal portio and mmio intercepts Paul Durrant
2015-06-17 14:22 ` Jan Beulich
2015-06-17 14:40 ` Paul Durrant
2015-06-17 14:55 ` Jan Beulich
2015-06-11 15:42 ` [PATCH v2 04/17] x86/hvm: unify dpci portio intercept with standard portio intercept Paul Durrant
2015-06-17 14:36 ` Jan Beulich
2015-06-17 14:46 ` Paul Durrant
2015-06-17 14:58 ` Jan Beulich
2015-06-17 15:17 ` Paul Durrant
2015-06-11 15:42 ` [PATCH v2 05/17] x86/hvm: unify stdvga mmio intercept with standard mmio intercept Paul Durrant
2015-06-17 15:50 ` Jan Beulich
2015-06-17 16:30 ` Paul Durrant
2015-06-18 6:23 ` Jan Beulich
2015-06-11 15:42 ` [PATCH v2 06/17] x86/hvm: revert 82ed8716b "fix direct PCI port I/O emulation retry Paul Durrant
2015-06-17 10:54 ` Paul Durrant
2015-06-11 15:42 ` [PATCH v2 07/17] x86/hvm: only call hvm_io_assist() from hvm_wait_for_io() Paul Durrant
2015-06-11 15:42 ` [PATCH v2 08/17] x86/hvm: split I/O completion handling from state model Paul Durrant
2015-06-11 15:42 ` [PATCH v2 09/17] x86/hvm: remove hvm_io_pending() check in hvmemul_do_io() Paul Durrant
2015-06-11 15:42 ` [PATCH v2 10/17] x86/hvm: remove HVMIO_dispatched I/O state Paul Durrant
2015-06-11 15:42 ` [PATCH v2 11/17] x86/hvm: remove hvm_io_state enumeration Paul Durrant
2015-06-11 15:42 ` [PATCH v2 12/17] x86/hvm: use ioreq_t to track in-flight state Paul Durrant
2015-06-11 15:42 ` [PATCH v2 13/17] x86/hvm: only acquire RAM pages for emulation when we need to Paul Durrant
2015-06-11 15:42 ` [PATCH v2 14/17] x86/hvm: remove extraneous parameter from hvmtrace_io_assist() Paul Durrant
2015-06-11 15:42 ` [PATCH v2 15/17] x86/hvm: make sure translated MMIO reads or writes fall within a page Paul Durrant
2015-06-11 15:43 ` [PATCH v2 16/17] x86/hvm: remove multiple open coded 'chunking' loops Paul Durrant
2015-06-11 15:43 ` Paul Durrant [this message]
2015-06-12 10:44 ` [PATCH v2 00/17] x86/hvm: I/O emulation cleanup and fix Fabio Fantoni
2015-06-12 11:45 ` Paul Durrant
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