From: Nicholas Piggin <npiggin@gmail.com>
To: kvm-ppc@vger.kernel.org
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>,
linuxppc-dev@lists.ozlabs.org,
Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH v4 24/46] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC
Date: Tue, 23 Mar 2021 11:02:43 +1000 [thread overview]
Message-ID: <20210323010305.1045293-25-npiggin@gmail.com> (raw)
In-Reply-To: <20210323010305.1045293-1-npiggin@gmail.com>
On processors that don't suppress the HDEC exceptions when LPCR[HDICE]=0,
this could help reduce needless guest exits due to leftover exceptions on
entering the guest.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/time.h | 2 ++
arch/powerpc/kvm/book3s_hv.c | 3 ++-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 8dd3cdb25338..68d94711811e 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -18,6 +18,8 @@
#include <asm/vdso/timebase.h>
/* time.c */
+extern u64 decrementer_max;
+
extern unsigned long tb_ticks_per_jiffy;
extern unsigned long tb_ticks_per_usec;
extern unsigned long tb_ticks_per_sec;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 8215430e6d5e..bb30c5ab53d1 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3658,7 +3658,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
vc->tb_offset_applied = 0;
}
- mtspr(SPRN_HDEC, 0x7fffffff);
+ /* HDEC must be at least as large as DEC, so decrementer_max fits */
+ mtspr(SPRN_HDEC, decrementer_max);
switch_mmu_to_host_radix(kvm, host_pidr);
--
2.23.0
next prev parent reply other threads:[~2021-03-23 1:14 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-23 1:02 [PATCH v4 00/46] KVM: PPC: Book3S: C-ify the P9 entry/exit code Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 01/46] KVM: PPC: Book3S HV: Nested move LPCR sanitising to sanitise_hv_regs Nicholas Piggin
2021-03-23 18:08 ` Fabiano Rosas
2021-03-31 2:47 ` Paul Mackerras
2021-03-23 1:02 ` [PATCH v4 02/46] KVM: PPC: Book3S HV: Add a function to filter guest LPCR bits Nicholas Piggin
2021-03-23 18:17 ` Fabiano Rosas
2021-03-31 4:08 ` Paul Mackerras
2021-04-01 9:32 ` Nicholas Piggin
2021-04-01 13:28 ` Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 03/46] KVM: PPC: Book3S HV: Disallow LPCR[AIL] to be set to 1 or 2 Nicholas Piggin
2021-03-31 4:28 ` Paul Mackerras
2021-03-23 1:02 ` [PATCH v4 04/46] KVM: PPC: Book3S HV: Prevent radix guests from setting LPCR[TC] Nicholas Piggin
2021-03-23 8:36 ` Alexey Kardashevskiy
2021-03-31 4:34 ` Paul Mackerras
2021-04-01 9:45 ` Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 05/46] KVM: PPC: Book3S HV: Remove redundant mtspr PSPB Nicholas Piggin
2021-03-31 4:35 ` Paul Mackerras
2021-03-23 1:02 ` [PATCH v4 06/46] KVM: PPC: Book3S HV: remove unused kvmppc_h_protect argument Nicholas Piggin
2021-03-31 4:38 ` Paul Mackerras
2021-03-23 1:02 ` [PATCH v4 07/46] KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcalls Nicholas Piggin
2021-03-31 4:39 ` Paul Mackerras
2021-03-23 1:02 ` [PATCH v4 08/46] powerpc/64s: Remove KVM handler support from CBE_RAS interrupts Nicholas Piggin
2021-03-31 4:41 ` Paul Mackerras
2021-03-23 1:02 ` [PATCH v4 09/46] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler Nicholas Piggin
2021-03-31 4:54 ` Paul Mackerras
2021-04-01 9:47 ` Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 10/46] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR Nicholas Piggin
2021-03-31 4:56 ` Paul Mackerras
2021-03-23 1:02 ` [PATCH v4 11/46] KVM: PPC: Book3S HV: Ensure MSR[HV] is always clear " Nicholas Piggin
2021-03-31 4:58 ` Paul Mackerras
2021-04-01 9:49 ` Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 12/46] KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point Nicholas Piggin
2021-04-01 4:29 ` Paul Mackerras
2021-03-23 1:02 ` [PATCH v4 13/46] KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM Nicholas Piggin
2021-04-01 5:32 ` Paul Mackerras
2021-04-01 9:53 ` Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 14/46] KVM: PPC: Book3S 64: add hcall interrupt handler Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 15/46] KVM: PPC: Book3S 64: Move hcall early register setup to KVM Nicholas Piggin
2021-04-01 5:41 ` Paul Mackerras
2021-04-01 10:03 ` Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 16/46] KVM: PPC: Book3S 64: Move interrupt " Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 17/46] KVM: PPC: Book3S 64: move bad_host_intr check to HV handler Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 18/46] KVM: PPC: Book3S 64: Minimise hcall handler calling convention differences Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 19/46] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 20/46] KVM: PPC: Book3S HV P9: implement kvmppc_xive_pull_vcpu in C Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 21/46] KVM: PPC: Book3S HV P9: Move xive vcpu context management into kvmhv_p9_guest_entry Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 22/46] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path Nicholas Piggin
2021-03-23 9:02 ` Alexey Kardashevskiy
2021-03-23 9:16 ` Nicholas Piggin
2021-03-23 9:24 ` Alexey Kardashevskiy
2021-03-23 9:48 ` Nicholas Piggin
2021-03-23 13:23 ` Cédric Le Goater
2021-03-24 1:21 ` Nicholas Piggin
2021-03-23 18:03 ` Fabiano Rosas
2021-03-24 1:22 ` Nicholas Piggin
2021-03-23 22:57 ` Fabiano Rosas
2021-03-24 1:27 ` Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 23/46] KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCR Nicholas Piggin
2021-03-23 1:02 ` Nicholas Piggin [this message]
2021-03-26 2:05 ` [PATCH v4 24/46] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC Alexey Kardashevskiy
2021-04-01 10:14 ` Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 25/46] KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 26/46] KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 27/46] powerpc: add set_dec_or_work API for safely updating decrementer Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 28/46] KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer races Nicholas Piggin
2021-03-23 10:13 ` Alexey Kardashevskiy
2021-03-23 10:36 ` Nicholas Piggin
2021-03-23 11:15 ` Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 29/46] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C Nicholas Piggin
2021-04-01 5:30 ` Alexey Kardashevskiy
2021-04-01 10:35 ` Nicholas Piggin
2021-04-02 4:36 ` Alexey Kardashevskiy
2021-04-02 7:58 ` Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 30/46] KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into __kvmhv_vcpu_entry_p9 Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 31/46] KVM: PPC: Book3S HV P9: Read machine check registers while MSR[RI] is 0 Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 32/46] KVM: PPC: Book3S HV P9: Improve exit timing accounting coverage Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 33/46] KVM: PPC: Book3S HV P9: Move SPR loading after expiry time check Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 34/46] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 35/46] KVM: PPC: Book3S HV P9: Switch to guest MMU context as late as possible Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 36/46] KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMU Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 37/46] KVM: PPC: Book3S HV: Remove support for dependent threads mode on P9 Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 38/46] KVM: PPC: Book3S HV: Remove radix guest support from P7/8 path Nicholas Piggin
2021-03-23 1:02 ` [PATCH v4 39/46] KVM: PPC: Book3S HV: Remove virt mode checks from real mode handlers Nicholas Piggin
2021-03-23 13:38 ` Cédric Le Goater
2021-03-23 1:02 ` [PATCH v4 40/46] KVM: PPC: Book3S HV: Remove unused nested HV tests in XICS emulation Nicholas Piggin
2021-03-23 1:03 ` [PATCH v4 41/46] KVM: PPC: Book3S HV P9: Allow all P9 processors to enable nested HV Nicholas Piggin
2021-03-23 1:03 ` [PATCH v4 42/46] KVM: PPC: Book3S HV: small pseries_do_hcall cleanup Nicholas Piggin
2021-03-23 1:03 ` [PATCH v4 43/46] KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faults Nicholas Piggin
2021-03-23 1:03 ` [PATCH v4 44/46] KVM: PPC: Book3S HV P9: implement hash guest support Nicholas Piggin
2021-03-23 15:53 ` Fabiano Rosas
2021-03-24 1:34 ` Nicholas Piggin
2021-03-23 1:03 ` [PATCH v4 45/46] KVM: PPC: Book3S HV P9: implement hash host / " Nicholas Piggin
2021-03-23 1:03 ` [PATCH v4 46/46] KVM: PPC: Book3S HV: remove ISA v3.0 and v3.1 support from P7/8 path Nicholas Piggin
2021-03-24 16:25 ` [PATCH v4 00/46] KVM: PPC: Book3S: C-ify the P9 entry/exit code Nicholas Piggin
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