| Message ID | 20210823164157.751807-5-philmd@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | physmem: Have flaview API check bus permission from MemTxAttrs argument | expand |
On Mon, Aug 23, 2021 at 06:41:56PM +0200, Philippe Mathieu-Daudé wrote: > Introduce flatview_access_allowed() to check bus permission > before running any bus transaction. For now this is a simple > stub. > > Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Shall we squash this patch into the next one? It helps explain better on why it's needed. Thanks,
On 23.08.21 20:43, Peter Xu wrote: > On Mon, Aug 23, 2021 at 06:41:56PM +0200, Philippe Mathieu-Daudé wrote: >> Introduce flatview_access_allowed() to check bus permission >> before running any bus transaction. For now this is a simple >> stub. >> >> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> > > Shall we squash this patch into the next one? It helps explain better on why > it's needed. Thanks, > I'd even go one step further and squash 3-5 into a single one.
On Mon, Aug 23, 2021 at 06:41:56PM +0200, Philippe Mathieu-Daudé wrote: > Introduce flatview_access_allowed() to check bus permission > before running any bus transaction. For now this is a simple > stub. > > Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> > --- > softmmu/physmem.c | 37 +++++++++++++++++++++++++++++++++++-- > 1 file changed, 35 insertions(+), 2 deletions(-) > > diff --git a/softmmu/physmem.c b/softmmu/physmem.c > index e534dc69918..0d31a2f4199 100644 > --- a/softmmu/physmem.c > +++ b/softmmu/physmem.c > @@ -2754,6 +2754,27 @@ static bool prepare_mmio_access(MemoryRegion *mr) > return release_lock; > } > > +/** > + * flatview_access_allowed > + * @mr: #MemoryRegion to be accessed > + * @attrs: memory transaction attributes > + * @addr: address within that memory region > + * @len: the number of bytes to access > + * @result: optional pointer to a MemTxResult or NULL > + * > + * Check if a memory transaction is allowed. If an error occurs this > + * method will return false to indicate denial, as well as setting > + * @result to contain corresponding #MemTxResult. > + * > + * Returns: true if transaction is allowed, false if denied. > + */ > +static inline bool flatview_access_allowed(MemoryRegion *mr, MemTxAttrs attrs, > + hwaddr addr, hwaddr len, > + MemTxResult *result) > +{ > + return true; > +} The callers below don't benefit from the result pointer argument. The code would be clearer if they did: if (!flatview_access_allowed(...)) { return MEMTX_BUS_ERROR; } > + > /* Called within RCU critical section. */ > static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr, > MemTxAttrs attrs, > @@ -2768,7 +2789,9 @@ static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr, > const uint8_t *buf = ptr; > > for (;;) { > - if (!memory_access_is_direct(mr, true)) { > + if (!flatview_access_allowed(mr, attrs, addr1, l, &result)) { > + /* 'result' contains the error, keep going. */ > + } else if (!memory_access_is_direct(mr, true)) { > release_lock |= prepare_mmio_access(mr); > l = memory_access_size(mr, l, addr1); > /* XXX: could force current_cpu to NULL to avoid > @@ -2810,9 +2833,13 @@ static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs, > hwaddr l; > hwaddr addr1; > MemoryRegion *mr; > + MemTxResult result = MEMTX_OK; > > l = len; > mr = flatview_translate(fv, addr, &addr1, &l, true, attrs); > + if (!flatview_access_allowed(mr, attrs, addr, len, &result)) { > + return result; > + } > return flatview_write_continue(fv, addr, attrs, buf, len, > addr1, l, mr); > } > @@ -2831,7 +2858,9 @@ MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr, > > fuzz_dma_read_cb(addr, len, mr); > for (;;) { > - if (!memory_access_is_direct(mr, false)) { > + if (!flatview_access_allowed(mr, attrs, addr1, l, &result)) { > + /* 'result' contains the error, keep going. */ > + } else if (!memory_access_is_direct(mr, false)) { > /* I/O case */ > release_lock |= prepare_mmio_access(mr); > l = memory_access_size(mr, l, addr1); > @@ -2871,9 +2900,13 @@ static MemTxResult flatview_read(FlatView *fv, hwaddr addr, > hwaddr l; > hwaddr addr1; > MemoryRegion *mr; > + MemTxResult result = MEMTX_OK; > > l = len; > mr = flatview_translate(fv, addr, &addr1, &l, false, attrs); > + if (!flatview_access_allowed(mr, attrs, addr, len, &result)) { > + return result; > + } > return flatview_read_continue(fv, addr, attrs, buf, len, > addr1, l, mr); > } > -- > 2.31.1 >
diff --git a/softmmu/physmem.c b/softmmu/physmem.c index e534dc69918..0d31a2f4199 100644 --- a/softmmu/physmem.c +++ b/softmmu/physmem.c @@ -2754,6 +2754,27 @@ static bool prepare_mmio_access(MemoryRegion *mr) return release_lock; } +/** + * flatview_access_allowed + * @mr: #MemoryRegion to be accessed + * @attrs: memory transaction attributes + * @addr: address within that memory region + * @len: the number of bytes to access + * @result: optional pointer to a MemTxResult or NULL + * + * Check if a memory transaction is allowed. If an error occurs this + * method will return false to indicate denial, as well as setting + * @result to contain corresponding #MemTxResult. + * + * Returns: true if transaction is allowed, false if denied. + */ +static inline bool flatview_access_allowed(MemoryRegion *mr, MemTxAttrs attrs, + hwaddr addr, hwaddr len, + MemTxResult *result) +{ + return true; +} + /* Called within RCU critical section. */ static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr, MemTxAttrs attrs, @@ -2768,7 +2789,9 @@ static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr, const uint8_t *buf = ptr; for (;;) { - if (!memory_access_is_direct(mr, true)) { + if (!flatview_access_allowed(mr, attrs, addr1, l, &result)) { + /* 'result' contains the error, keep going. */ + } else if (!memory_access_is_direct(mr, true)) { release_lock |= prepare_mmio_access(mr); l = memory_access_size(mr, l, addr1); /* XXX: could force current_cpu to NULL to avoid @@ -2810,9 +2833,13 @@ static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs, hwaddr l; hwaddr addr1; MemoryRegion *mr; + MemTxResult result = MEMTX_OK; l = len; mr = flatview_translate(fv, addr, &addr1, &l, true, attrs); + if (!flatview_access_allowed(mr, attrs, addr, len, &result)) { + return result; + } return flatview_write_continue(fv, addr, attrs, buf, len, addr1, l, mr); } @@ -2831,7 +2858,9 @@ MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr, fuzz_dma_read_cb(addr, len, mr); for (;;) { - if (!memory_access_is_direct(mr, false)) { + if (!flatview_access_allowed(mr, attrs, addr1, l, &result)) { + /* 'result' contains the error, keep going. */ + } else if (!memory_access_is_direct(mr, false)) { /* I/O case */ release_lock |= prepare_mmio_access(mr); l = memory_access_size(mr, l, addr1); @@ -2871,9 +2900,13 @@ static MemTxResult flatview_read(FlatView *fv, hwaddr addr, hwaddr l; hwaddr addr1; MemoryRegion *mr; + MemTxResult result = MEMTX_OK; l = len; mr = flatview_translate(fv, addr, &addr1, &l, false, attrs); + if (!flatview_access_allowed(mr, attrs, addr, len, &result)) { + return result; + } return flatview_read_continue(fv, addr, attrs, buf, len, addr1, l, mr); }
Introduce flatview_access_allowed() to check bus permission before running any bus transaction. For now this is a simple stub. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> --- softmmu/physmem.c | 37 +++++++++++++++++++++++++++++++++++-- 1 file changed, 35 insertions(+), 2 deletions(-)