From 69b4ed0259f89925640556751e7018f3acd715f1 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 7 Mar 2025 10:08:20 +0000 Subject: [PATCH] target/arm: Always apply CNTVOFF_EL2 for CNTV_TVAL_EL02 accesses MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Currently we handle CNTV_TVAL_EL02 by calling gt_tval_read() for the EL1 virt timer. This is almost correct, but the underlying CNTV_TVAL_EL0 register behaves slightly differently. CNTV_TVAL_EL02 always applies the CNTVOFF_EL2 offset; CNTV_TVAL_EL0 doesn't do so if we're at EL2 and HCR_EL2.E2H is 1. We were getting this wrong, because we ended up in gt_virt_cnt_offset() and did the E2H check. Factor out the tval read/write calculation from the selection of the offset, so that we can special case gt_virt_tval_read() and gt_virt_tval_write() to unconditionally pass CNTVOFF_EL2. Cc: qemu-stable@nongnu.org Signed-off-by: Peter Maydell Reviewed-by: Alex Bennée Message-id: 20250204125009.2281315-5-peter.maydell@linaro.org (cherry picked from commit 4aecd4b442d7abb4355896d878ffc9b028625b01) Signed-off-by: Michael Tokarev --- target/arm/helper.c | 36 +++++++++++++++++++++++++++--------- 1 file changed, 27 insertions(+), 9 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index a881e890e9..6f741f5c00 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -2867,6 +2867,12 @@ static void gt_cval_write(CPUARMState *env, const ARMCPRegInfo *ri, gt_recalc_timer(env_archcpu(env), timeridx); } +static uint64_t do_tval_read(CPUARMState *env, int timeridx, uint64_t offset) +{ + return (uint32_t)(env->cp15.c14_timer[timeridx].cval - + (gt_get_countervalue(env) - offset)); +} + static uint64_t gt_tval_read(CPUARMState *env, const ARMCPRegInfo *ri, int timeridx) { @@ -2881,8 +2887,16 @@ static uint64_t gt_tval_read(CPUARMState *env, const ARMCPRegInfo *ri, break; } - return (uint32_t)(env->cp15.c14_timer[timeridx].cval - - (gt_get_countervalue(env) - offset)); + return do_tval_read(env, timeridx, offset); +} + +static void do_tval_write(CPUARMState *env, int timeridx, uint64_t value, + uint64_t offset) +{ + trace_arm_gt_tval_write(timeridx, value); + env->cp15.c14_timer[timeridx].cval = gt_get_countervalue(env) - offset + + sextract64(value, 0, 32); + gt_recalc_timer(env_archcpu(env), timeridx); } static void gt_tval_write(CPUARMState *env, const ARMCPRegInfo *ri, @@ -2899,11 +2913,7 @@ static void gt_tval_write(CPUARMState *env, const ARMCPRegInfo *ri, offset = gt_phys_cnt_offset(env); break; } - - trace_arm_gt_tval_write(timeridx, value); - env->cp15.c14_timer[timeridx].cval = gt_get_countervalue(env) - offset + - sextract64(value, 0, 32); - gt_recalc_timer(env_archcpu(env), timeridx); + do_tval_write(env, timeridx, value, offset); } static void gt_ctl_write(CPUARMState *env, const ARMCPRegInfo *ri, @@ -3035,13 +3045,21 @@ static void gt_virt_cval_write(CPUARMState *env, const ARMCPRegInfo *ri, static uint64_t gt_virt_tval_read(CPUARMState *env, const ARMCPRegInfo *ri) { - return gt_tval_read(env, ri, GTIMER_VIRT); + /* + * This is CNTV_TVAL_EL02; unlike the underlying CNTV_TVAL_EL0 + * we always apply CNTVOFF_EL2. Special case that here rather + * than going into the generic gt_tval_read() and then having + * to re-detect that it's this register. + * Note that the accessfn/perms mean we know we're at EL2 or EL3 here. + */ + return do_tval_read(env, GTIMER_VIRT, env->cp15.cntvoff_el2); } static void gt_virt_tval_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value) { - gt_tval_write(env, ri, GTIMER_VIRT, value); + /* Similarly for writes to CNTV_TVAL_EL02 */ + do_tval_write(env, GTIMER_VIRT, value, env->cp15.cntvoff_el2); } static void gt_virt_ctl_write(CPUARMState *env, const ARMCPRegInfo *ri, -- 2.39.5