target/ppc/timebase_helper.c | 40 +++++++++++++++++++++++------------- 1 file changed, 26 insertions(+), 14 deletions(-)
The ppc_dcr_read() and ppc_dcr_write() functions call into callbacks
in device code, so we need to hold the QEMU iothread lock while
calling them. This is the case already for the callsites in
kvmppc_handle_dcr_read/write(), but we must also take the lock when
calling the helpers from TCG.
This fixes a bug where attempting to initialise the PPC405EP
SDRAM will cause an assertion when sdram_map_bcr() attempts
to remap memory regions.
Reported-by: Amit Lazar <abasarlaz@hotmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
Amit reported this bug via IRC.
target/ppc/timebase_helper.c | 40 +++++++++++++++++++++++-------------
1 file changed, 26 insertions(+), 14 deletions(-)
diff --git a/target/ppc/timebase_helper.c b/target/ppc/timebase_helper.c
index 703bd9ed18b..d16360ab667 100644
--- a/target/ppc/timebase_helper.c
+++ b/target/ppc/timebase_helper.c
@@ -21,6 +21,7 @@
#include "exec/helper-proto.h"
#include "exec/exec-all.h"
#include "qemu/log.h"
+#include "qemu/main-loop.h"
/*****************************************************************************/
/* SPR accesses */
@@ -167,13 +168,19 @@ target_ulong helper_load_dcr(CPUPPCState *env, target_ulong dcrn)
raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
POWERPC_EXCP_INVAL |
POWERPC_EXCP_INVAL_INVAL, GETPC());
- } else if (unlikely(ppc_dcr_read(env->dcr_env,
- (uint32_t)dcrn, &val) != 0)) {
- qemu_log_mask(LOG_GUEST_ERROR, "DCR read error %d %03x\n",
- (uint32_t)dcrn, (uint32_t)dcrn);
- raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
- POWERPC_EXCP_INVAL |
- POWERPC_EXCP_PRIV_REG, GETPC());
+ } else {
+ int ret;
+
+ qemu_mutex_lock_iothread();
+ ret = ppc_dcr_read(env->dcr_env, (uint32_t)dcrn, &val);
+ qemu_mutex_unlock_iothread();
+ if (unlikely(ret != 0)) {
+ qemu_log_mask(LOG_GUEST_ERROR, "DCR read error %d %03x\n",
+ (uint32_t)dcrn, (uint32_t)dcrn);
+ raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
+ POWERPC_EXCP_INVAL |
+ POWERPC_EXCP_PRIV_REG, GETPC());
+ }
}
return val;
}
@@ -185,12 +192,17 @@ void helper_store_dcr(CPUPPCState *env, target_ulong dcrn, target_ulong val)
raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
POWERPC_EXCP_INVAL |
POWERPC_EXCP_INVAL_INVAL, GETPC());
- } else if (unlikely(ppc_dcr_write(env->dcr_env, (uint32_t)dcrn,
- (uint32_t)val) != 0)) {
- qemu_log_mask(LOG_GUEST_ERROR, "DCR write error %d %03x\n",
- (uint32_t)dcrn, (uint32_t)dcrn);
- raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
- POWERPC_EXCP_INVAL |
- POWERPC_EXCP_PRIV_REG, GETPC());
+ } else {
+ int ret;
+ qemu_mutex_lock_iothread();
+ ret = ppc_dcr_write(env->dcr_env, (uint32_t)dcrn, (uint32_t)val);
+ qemu_mutex_unlock_iothread();
+ if (unlikely(ret != 0)) {
+ qemu_log_mask(LOG_GUEST_ERROR, "DCR write error %d %03x\n",
+ (uint32_t)dcrn, (uint32_t)dcrn);
+ raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
+ POWERPC_EXCP_INVAL |
+ POWERPC_EXCP_PRIV_REG, GETPC());
+ }
}
}
--
2.20.1
On Sun, Mar 22, 2020 at 07:22:58PM +0000, Peter Maydell wrote: > The ppc_dcr_read() and ppc_dcr_write() functions call into callbacks > in device code, so we need to hold the QEMU iothread lock while > calling them. This is the case already for the callsites in > kvmppc_handle_dcr_read/write(), but we must also take the lock when > calling the helpers from TCG. > > This fixes a bug where attempting to initialise the PPC405EP > SDRAM will cause an assertion when sdram_map_bcr() attempts > to remap memory regions. > > Reported-by: Amit Lazar <abasarlaz@hotmail.com> > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Applied to ppc-for-5.0. > --- > Amit reported this bug via IRC. > > target/ppc/timebase_helper.c | 40 +++++++++++++++++++++++------------- > 1 file changed, 26 insertions(+), 14 deletions(-) > > diff --git a/target/ppc/timebase_helper.c b/target/ppc/timebase_helper.c > index 703bd9ed18b..d16360ab667 100644 > --- a/target/ppc/timebase_helper.c > +++ b/target/ppc/timebase_helper.c > @@ -21,6 +21,7 @@ > #include "exec/helper-proto.h" > #include "exec/exec-all.h" > #include "qemu/log.h" > +#include "qemu/main-loop.h" > > /*****************************************************************************/ > /* SPR accesses */ > @@ -167,13 +168,19 @@ target_ulong helper_load_dcr(CPUPPCState *env, target_ulong dcrn) > raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM, > POWERPC_EXCP_INVAL | > POWERPC_EXCP_INVAL_INVAL, GETPC()); > - } else if (unlikely(ppc_dcr_read(env->dcr_env, > - (uint32_t)dcrn, &val) != 0)) { > - qemu_log_mask(LOG_GUEST_ERROR, "DCR read error %d %03x\n", > - (uint32_t)dcrn, (uint32_t)dcrn); > - raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM, > - POWERPC_EXCP_INVAL | > - POWERPC_EXCP_PRIV_REG, GETPC()); > + } else { > + int ret; > + > + qemu_mutex_lock_iothread(); > + ret = ppc_dcr_read(env->dcr_env, (uint32_t)dcrn, &val); > + qemu_mutex_unlock_iothread(); > + if (unlikely(ret != 0)) { > + qemu_log_mask(LOG_GUEST_ERROR, "DCR read error %d %03x\n", > + (uint32_t)dcrn, (uint32_t)dcrn); > + raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM, > + POWERPC_EXCP_INVAL | > + POWERPC_EXCP_PRIV_REG, GETPC()); > + } > } > return val; > } > @@ -185,12 +192,17 @@ void helper_store_dcr(CPUPPCState *env, target_ulong dcrn, target_ulong val) > raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM, > POWERPC_EXCP_INVAL | > POWERPC_EXCP_INVAL_INVAL, GETPC()); > - } else if (unlikely(ppc_dcr_write(env->dcr_env, (uint32_t)dcrn, > - (uint32_t)val) != 0)) { > - qemu_log_mask(LOG_GUEST_ERROR, "DCR write error %d %03x\n", > - (uint32_t)dcrn, (uint32_t)dcrn); > - raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM, > - POWERPC_EXCP_INVAL | > - POWERPC_EXCP_PRIV_REG, GETPC()); > + } else { > + int ret; > + qemu_mutex_lock_iothread(); > + ret = ppc_dcr_write(env->dcr_env, (uint32_t)dcrn, (uint32_t)val); > + qemu_mutex_unlock_iothread(); > + if (unlikely(ret != 0)) { > + qemu_log_mask(LOG_GUEST_ERROR, "DCR write error %d %03x\n", > + (uint32_t)dcrn, (uint32_t)dcrn); > + raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM, > + POWERPC_EXCP_INVAL | > + POWERPC_EXCP_PRIV_REG, GETPC()); > + } > } > } -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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