| Message ID | 20190506173353.32206-24-richard.henderson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add qemu_getrandom and ARMv8.5-RNG etc | expand |
On 06/05/2019 19:33, Richard Henderson wrote: > We now have an interface for guest visible random numbers. > > Acked-by: David Gibson <david@gibson.dropbear.id.au> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > target/ppc/int_helper.c | 42 +++++++++++++++++++++++++++++------------ > 1 file changed, 30 insertions(+), 12 deletions(-) > > diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c > index f6a088ac08..9059e70b9c 100644 > --- a/target/ppc/int_helper.c > +++ b/target/ppc/int_helper.c > @@ -23,6 +23,8 @@ > #include "exec/helper-proto.h" > #include "crypto/aes.h" > #include "fpu/softfloat.h" > +#include "qapi/error.h" > +#include "qemu/guest-random.h" > > #include "helper_regs.h" > /*****************************************************************************/ > @@ -158,25 +160,41 @@ uint32_t helper_cmpeqb(target_ulong ra, target_ulong rb) > #undef hasvalue > > /* > - * Return invalid random number. > - * > - * FIXME: Add rng backend or other mechanism to get cryptographically suitable > - * random number > + * Return a random number. > */ > -target_ulong helper_darn32(void) > +uint64_t helper_darn32(void) > { > - return -1; > + Error *err = NULL; > + uint32_t ret; > + > + if (qemu_guest_getrandom(&ret, 4, &err) < 0) { sizeof(ret)? > + qemu_log_mask(LOG_UNIMP, "darn: Crypto failure: %s", > + error_get_pretty(err)); > + error_free(err); > + return -1; > + } > + > + return ret; > } > > -target_ulong helper_darn64(void) > +uint64_t helper_darn64(void) > { > - return -1; > + Error *err = NULL; > + uint64_t ret; > + > + do { > + if (qemu_guest_getrandom(&ret, 8, &err) < 0) { sizeof(ret)? > + qemu_log_mask(LOG_UNIMP, "darn: Crypto failure: %s", > + error_get_pretty(err)); > + error_free(err); > + return -1; > + } > + /* Since -1 is the error condition, try again for that case. */ > + } while (unlikely(ret == -1)); I think you don't need to do that, according to documentation, this is done by the software: "Programming Note: When the error value is obtained, software is expected to repeat the operation. [...]" - PowerISA Version 3.0B Thanks, Laurent
diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c index f6a088ac08..9059e70b9c 100644 --- a/target/ppc/int_helper.c +++ b/target/ppc/int_helper.c @@ -23,6 +23,8 @@ #include "exec/helper-proto.h" #include "crypto/aes.h" #include "fpu/softfloat.h" +#include "qapi/error.h" +#include "qemu/guest-random.h" #include "helper_regs.h" /*****************************************************************************/ @@ -158,25 +160,41 @@ uint32_t helper_cmpeqb(target_ulong ra, target_ulong rb) #undef hasvalue /* - * Return invalid random number. - * - * FIXME: Add rng backend or other mechanism to get cryptographically suitable - * random number + * Return a random number. */ -target_ulong helper_darn32(void) +uint64_t helper_darn32(void) { - return -1; + Error *err = NULL; + uint32_t ret; + + if (qemu_guest_getrandom(&ret, 4, &err) < 0) { + qemu_log_mask(LOG_UNIMP, "darn: Crypto failure: %s", + error_get_pretty(err)); + error_free(err); + return -1; + } + + return ret; } -target_ulong helper_darn64(void) +uint64_t helper_darn64(void) { - return -1; + Error *err = NULL; + uint64_t ret; + + do { + if (qemu_guest_getrandom(&ret, 8, &err) < 0) { + qemu_log_mask(LOG_UNIMP, "darn: Crypto failure: %s", + error_get_pretty(err)); + error_free(err); + return -1; + } + /* Since -1 is the error condition, try again for that case. */ + } while (unlikely(ret == -1)); + + return ret; } -#endif - -#if defined(TARGET_PPC64) - uint64_t helper_bpermd(uint64_t rs, uint64_t rb) { int i;