A chained event overflowing on the low counter can set the overflow flag in PMOVS. KVM does not set it, but real HW and the fast-model seem to. Moreover, the AArch64.IncrementEventCounter() pseudocode in the ARM ARM (DDI 0487H.a, J1.1.1 "aarch64/debug") also sets the PMOVS bit on overflow. The pmu chain tests fail on bare metal when checking the overflow flag of the low counter _not_ being set on overflow. Fix by checking for overflow. Note that this test fails in KVM without the respective fix. Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx> --- arm/pmu.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) diff --git a/arm/pmu.c b/arm/pmu.c index 7c5bc259..258780f4 100644 --- a/arm/pmu.c +++ b/arm/pmu.c @@ -583,7 +583,7 @@ static void test_chained_counters(void) precise_instrs_loop(22, pmu.pmcr_ro | PMU_PMCR_E); report(read_regn_el0(pmevcntr, 1) == 1, "CHAIN counter #1 incremented"); - report(!read_sysreg(pmovsclr_el0), "no overflow recorded for chained incr #1"); + report(read_sysreg(pmovsclr_el0) == 0x1, "overflow recorded for chained incr #1"); /* test 64b overflow */ @@ -595,7 +595,7 @@ static void test_chained_counters(void) precise_instrs_loop(22, pmu.pmcr_ro | PMU_PMCR_E); report_info("overflow reg = 0x%lx", read_sysreg(pmovsclr_el0)); report(read_regn_el0(pmevcntr, 1) == 2, "CHAIN counter #1 set to 2"); - report(!read_sysreg(pmovsclr_el0), "no overflow recorded for chained incr #2"); + report(read_sysreg(pmovsclr_el0) == 0x1, "overflow recorded for chained incr #2"); write_regn_el0(pmevcntr, 0, PRE_OVERFLOW); write_regn_el0(pmevcntr, 1, ALL_SET); @@ -603,7 +603,7 @@ static void test_chained_counters(void) precise_instrs_loop(22, pmu.pmcr_ro | PMU_PMCR_E); report_info("overflow reg = 0x%lx", read_sysreg(pmovsclr_el0)); report(!read_regn_el0(pmevcntr, 1), "CHAIN counter #1 wrapped"); - report(read_sysreg(pmovsclr_el0) == 0x2, "overflow on chain counter"); + report(read_sysreg(pmovsclr_el0) == 0x3, "overflow on even and odd counters"); } static void test_chained_sw_incr(void) @@ -629,8 +629,9 @@ static void test_chained_sw_incr(void) write_sysreg(0x1, pmswinc_el0); isb(); - report(!read_sysreg(pmovsclr_el0) && (read_regn_el0(pmevcntr, 1) == 1), - "no overflow and chain counter incremented after 100 SW_INCR/CHAIN"); + report((read_sysreg(pmovsclr_el0) == 0x1) && + (read_regn_el0(pmevcntr, 1) == 1), + "overflow and chain counter incremented after 100 SW_INCR/CHAIN"); report_info("overflow=0x%lx, #0=%ld #1=%ld", read_sysreg(pmovsclr_el0), read_regn_el0(pmevcntr, 0), read_regn_el0(pmevcntr, 1)); @@ -648,10 +649,10 @@ static void test_chained_sw_incr(void) write_sysreg(0x1, pmswinc_el0); isb(); - report((read_sysreg(pmovsclr_el0) == 0x2) && + report((read_sysreg(pmovsclr_el0) == 0x3) && (read_regn_el0(pmevcntr, 1) == 0) && (read_regn_el0(pmevcntr, 0) == 84), - "overflow on chain counter and expected values after 100 SW_INCR/CHAIN"); + "overflow on even and odd counters, and expected values after 100 SW_INCR/CHAIN"); report_info("overflow=0x%lx, #0=%ld #1=%ld", read_sysreg(pmovsclr_el0), read_regn_el0(pmevcntr, 0), read_regn_el0(pmevcntr, 1)); } @@ -731,8 +732,9 @@ static void test_chain_promotion(void) report_info("MEM_ACCESS counter #0 has value 0x%lx", read_regn_el0(pmevcntr, 0)); - report((read_regn_el0(pmevcntr, 1) == 1) && !read_sysreg(pmovsclr_el0), - "CHAIN counter enabled: CHAIN counter was incremented and no overflow"); + report((read_regn_el0(pmevcntr, 1) == 1) && + (read_sysreg(pmovsclr_el0) == 0x1), + "CHAIN counter enabled: CHAIN counter was incremented and overflow"); report_info("CHAIN counter #1 = 0x%lx, overflow=0x%lx", read_regn_el0(pmevcntr, 1), read_sysreg(pmovsclr_el0)); @@ -759,8 +761,9 @@ static void test_chain_promotion(void) report_info("MEM_ACCESS counter #0 has value 0x%lx", read_regn_el0(pmevcntr, 0)); - report((read_regn_el0(pmevcntr, 1) == 1) && !read_sysreg(pmovsclr_el0), - "32b->64b: CHAIN counter incremented and no overflow"); + report((read_regn_el0(pmevcntr, 1) == 1) && + (read_sysreg(pmovsclr_el0) == 0x1), + "32b->64b: CHAIN counter incremented and overflow"); report_info("CHAIN counter #1 = 0x%lx, overflow=0x%lx", read_regn_el0(pmevcntr, 1), read_sysreg(pmovsclr_el0)); @@ -867,8 +870,8 @@ static void test_overflow_interrupt(void) write_regn_el0(pmevcntr, 0, PRE_OVERFLOW); isb(); mem_access_loop(addr, 200, pmu.pmcr_ro | PMU_PMCR_E); - report(expect_interrupts(0), - "no overflow interrupt expected on 32b boundary"); + report(expect_interrupts(0x1), + "expect overflow interrupt on 32b boundary"); /* overflow on odd counter */ pmu_reset_stats(); @@ -876,8 +879,8 @@ static void test_overflow_interrupt(void) write_regn_el0(pmevcntr, 1, ALL_SET); isb(); mem_access_loop(addr, 400, pmu.pmcr_ro | PMU_PMCR_E); - report(expect_interrupts(0x2), - "expect overflow interrupt on odd counter"); + report(expect_interrupts(0x3), + "expect overflow interrupt on even and odd counter"); } #endif -- 2.37.1.455.g008518b4e5-goog