From 857d1a973077245f03b351e2539529c86267bfe4 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 24 Aug 2015 14:42:05 +0100 Subject: arm64: KVM: set {v,}TCR_EL2 RES1 bits Currently we don't set the RES1 bits of TCR_EL2 and VTCR_EL2 when configuring them, which could lead to unexpected behaviour when an architectural meaning is defined for those bits. Set the RES1 bits to avoid issues. Cc: Catalin Marinas Cc: Christoffer Dall Cc: Marc Zyngier Cc: Suzuki Poulose Cc: Will Deacon Reviewed-by: Christoffer Dall Signed-off-by: Mark Rutland Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_arm.h | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 7605e095217f..cbc5e1a0ea8f 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -95,6 +95,7 @@ SCTLR_EL2_SA | SCTLR_EL2_I) /* TCR_EL2 Registers bits */ +#define TCR_EL2_RES1 ((1 << 31) | (1 << 23)) #define TCR_EL2_TBI (1 << 20) #define TCR_EL2_PS (7 << 16) #define TCR_EL2_PS_40B (2 << 16) @@ -106,9 +107,10 @@ #define TCR_EL2_MASK (TCR_EL2_TG0 | TCR_EL2_SH0 | \ TCR_EL2_ORGN0 | TCR_EL2_IRGN0 | TCR_EL2_T0SZ) -#define TCR_EL2_FLAGS (TCR_EL2_PS_40B) +#define TCR_EL2_FLAGS (TCR_EL2_RES1 | TCR_EL2_PS_40B) /* VTCR_EL2 Registers bits */ +#define VTCR_EL2_RES1 (1 << 31) #define VTCR_EL2_PS_MASK (7 << 16) #define VTCR_EL2_TG0_MASK (1 << 14) #define VTCR_EL2_TG0_4K (0 << 14) @@ -147,7 +149,8 @@ */ #define VTCR_EL2_FLAGS (VTCR_EL2_TG0_64K | VTCR_EL2_SH0_INNER | \ VTCR_EL2_ORGN0_WBWA | VTCR_EL2_IRGN0_WBWA | \ - VTCR_EL2_SL0_LVL1 | VTCR_EL2_T0SZ_40B) + VTCR_EL2_SL0_LVL1 | VTCR_EL2_T0SZ_40B | \ + VTCR_EL2_RES1) #define VTTBR_X (38 - VTCR_EL2_T0SZ_40B) #else /* @@ -158,7 +161,8 @@ */ #define VTCR_EL2_FLAGS (VTCR_EL2_TG0_4K | VTCR_EL2_SH0_INNER | \ VTCR_EL2_ORGN0_WBWA | VTCR_EL2_IRGN0_WBWA | \ - VTCR_EL2_SL0_LVL1 | VTCR_EL2_T0SZ_40B) + VTCR_EL2_SL0_LVL1 | VTCR_EL2_T0SZ_40B | \ + VTCR_EL2_RES1) #define VTTBR_X (37 - VTCR_EL2_T0SZ_40B) #endif -- cgit v1.2.3 From 43297dda0a51e4ffed0888ce727c218cfb7474b6 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 14 Sep 2015 16:06:03 +0100 Subject: KVM: arm64: add workaround for Cortex-A57 erratum #852523 When restoring the system register state for an AArch32 guest at EL2, writes to DACR32_EL2 may not be correctly synchronised by Cortex-A57, which can lead to the guest effectively running with junk in the DACR and running into unexpected domain faults. This patch works around the issue by re-ordering our restoration of the AArch32 register aliases so that they happen before the AArch64 system registers. Ensuring that the registers are restored in this order guarantees that they will be correctly synchronised by the core. Cc: Reviewed-by: Marc Zyngier Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp.S | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/arm64') diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index 8188f6ae8fc4..39aa322765f9 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -745,6 +745,9 @@ ENTRY(__kvm_vcpu_run) // Guest context add x2, x0, #VCPU_CONTEXT + // We must restore the 32-bit state before the sysregs, thanks + // to Cortex-A57 erratum #852523. + restore_guest_32bit_state bl __restore_sysregs skip_debug_state x3, 1f @@ -752,7 +755,6 @@ ENTRY(__kvm_vcpu_run) kern_hyp_va x3 bl __restore_debug 1: - restore_guest_32bit_state restore_guest_regs // That's it, no more messing around. -- cgit v1.2.3 From 62bea5bff486644ecf363fe8a1a2f6f32c614a49 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 15 Sep 2015 18:27:57 +0200 Subject: KVM: add halt_attempted_poll to VCPU stats This new statistic can help diagnosing VCPUs that, for any reason, trigger bad behavior of halt_poll_ns autotuning. For example, say halt_poll_ns = 480000, and wakeups are spaced exactly like 479us, 481us, 479us, 481us. Then KVM always fails polling and wastes 10+20+40+80+160+320+480 = 1110 microseconds out of every 479+481+479+481+479+481+479 = 3359 microseconds. The VCPU then is consuming about 30% more CPU than it would use without polling. This would show as an abnormally high number of attempted polling compared to the successful polls. Acked-by: Christian Borntraeger Signed-off-by: Paolo Bonzini --- arch/arm/include/asm/kvm_host.h | 1 + arch/arm64/include/asm/kvm_host.h | 1 + arch/mips/include/asm/kvm_host.h | 1 + arch/mips/kvm/mips.c | 1 + arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/kvm/book3s.c | 1 + arch/powerpc/kvm/booke.c | 1 + arch/s390/include/asm/kvm_host.h | 1 + arch/s390/kvm/kvm-s390.c | 1 + arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/x86.c | 1 + virt/kvm/kvm_main.c | 1 + 12 files changed, 12 insertions(+) (limited to 'arch/arm64') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index dcba0fa5176e..687ddeba3611 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -148,6 +148,7 @@ struct kvm_vm_stat { struct kvm_vcpu_stat { u32 halt_successful_poll; + u32 halt_attempted_poll; u32 halt_wakeup; }; diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 415938dc45cf..486594583cc6 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -195,6 +195,7 @@ struct kvm_vm_stat { struct kvm_vcpu_stat { u32 halt_successful_poll; + u32 halt_attempted_poll; u32 halt_wakeup; }; diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h index e8c8d9d0c45f..3a54dbca9f7e 100644 --- a/arch/mips/include/asm/kvm_host.h +++ b/arch/mips/include/asm/kvm_host.h @@ -128,6 +128,7 @@ struct kvm_vcpu_stat { u32 msa_disabled_exits; u32 flush_dcache_exits; u32 halt_successful_poll; + u32 halt_attempted_poll; u32 halt_wakeup; }; diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index cd4c129ce743..49ff3bfc007e 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -55,6 +55,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "msa_disabled", VCPU_STAT(msa_disabled_exits), KVM_STAT_VCPU }, { "flush_dcache", VCPU_STAT(flush_dcache_exits), KVM_STAT_VCPU }, { "halt_successful_poll", VCPU_STAT(halt_successful_poll), KVM_STAT_VCPU }, + { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll), KVM_STAT_VCPU }, { "halt_wakeup", VCPU_STAT(halt_wakeup), KVM_STAT_VCPU }, {NULL} }; diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 98eebbf66340..195886a583ba 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -108,6 +108,7 @@ struct kvm_vcpu_stat { u32 dec_exits; u32 ext_intr_exits; u32 halt_successful_poll; + u32 halt_attempted_poll; u32 halt_wakeup; u32 dbell_exits; u32 gdbell_exits; diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index d75bf325f54a..cf009167d208 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -53,6 +53,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "ext_intr", VCPU_STAT(ext_intr_exits) }, { "queue_intr", VCPU_STAT(queue_intr) }, { "halt_successful_poll", VCPU_STAT(halt_successful_poll), }, + { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll), }, { "halt_wakeup", VCPU_STAT(halt_wakeup) }, { "pf_storage", VCPU_STAT(pf_storage) }, { "sp_storage", VCPU_STAT(sp_storage) }, diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index ae458f0fd061..fd5875179e5c 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -63,6 +63,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "dec", VCPU_STAT(dec_exits) }, { "ext_intr", VCPU_STAT(ext_intr_exits) }, { "halt_successful_poll", VCPU_STAT(halt_successful_poll) }, + { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) }, { "halt_wakeup", VCPU_STAT(halt_wakeup) }, { "doorbell", VCPU_STAT(dbell_exits) }, { "guest doorbell", VCPU_STAT(gdbell_exits) }, diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 3d012e071647..6ce4a0b7e8da 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -210,6 +210,7 @@ struct kvm_vcpu_stat { u32 exit_validity; u32 exit_instruction; u32 halt_successful_poll; + u32 halt_attempted_poll; u32 halt_wakeup; u32 instruction_lctl; u32 instruction_lctlg; diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index c91eb941b444..2f807ab1725e 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -63,6 +63,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "exit_program_interruption", VCPU_STAT(exit_program_interruption) }, { "exit_instr_and_program_int", VCPU_STAT(exit_instr_and_program) }, { "halt_successful_poll", VCPU_STAT(halt_successful_poll) }, + { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) }, { "halt_wakeup", VCPU_STAT(halt_wakeup) }, { "instruction_lctlg", VCPU_STAT(instruction_lctlg) }, { "instruction_lctl", VCPU_STAT(instruction_lctl) }, diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index c12e845f59e6..349f80a82b82 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -711,6 +711,7 @@ struct kvm_vcpu_stat { u32 nmi_window_exits; u32 halt_exits; u32 halt_successful_poll; + u32 halt_attempted_poll; u32 halt_wakeup; u32 request_irq_exits; u32 irq_exits; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a60bdbccff51..6bbb0dfb99d0 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -149,6 +149,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "nmi_window", VCPU_STAT(nmi_window_exits) }, { "halt_exits", VCPU_STAT(halt_exits) }, { "halt_successful_poll", VCPU_STAT(halt_successful_poll) }, + { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) }, { "halt_wakeup", VCPU_STAT(halt_wakeup) }, { "hypercalls", VCPU_STAT(hypercalls) }, { "request_irq", VCPU_STAT(request_irq_exits) }, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 9af68db73c6a..04146a2e1d81 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2004,6 +2004,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) if (vcpu->halt_poll_ns) { ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns); + ++vcpu->stat.halt_attempted_poll; do { /* * This sets KVM_REQ_UNHALT if an interrupt -- cgit v1.2.3 From 1713e5aa05fff3951e747548b373bd2c81be4e7a Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 16 Sep 2015 10:54:37 +0100 Subject: arm64: KVM: Fix user access for debug registers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When setting the debug register from userspace, make sure that copy_from_user() is called with its parameters in the expected order. It otherwise doesn't do what you think. Fixes: 84e690bfbed1 ("KVM: arm64: introduce vcpu->arch.debug_ptr") Reported-by: Peter Maydell Cc: Alex Bennée Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index b41607d270ac..1d0463e6a9e3 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -272,7 +272,7 @@ static int set_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, { __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg]; - if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0) + if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0) return -EFAULT; return 0; } @@ -314,7 +314,7 @@ static int set_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, { __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg]; - if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0) + if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0) return -EFAULT; return 0; @@ -358,7 +358,7 @@ static int set_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, { __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg]; - if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0) + if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0) return -EFAULT; return 0; } @@ -400,7 +400,7 @@ static int set_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, { __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg]; - if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0) + if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0) return -EFAULT; return 0; } -- cgit v1.2.3 From c4cbba9fa078f55d9f6d081dbb4aec7cf969e7c7 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 16 Sep 2015 16:18:59 +0100 Subject: arm64: KVM: Disable virtual timer even if the guest is not using it When running a guest with the architected timer disabled (with QEMU and the kernel_irqchip=off option, for example), it is important to make sure the timer gets turned off. Otherwise, the guest may try to enable it anyway, leading to a screaming HW interrupt. The fix is to unconditionally turn off the virtual timer on guest exit. Cc: stable@vger.kernel.org Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp.S | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index 39aa322765f9..60a83e2900a7 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -562,8 +562,6 @@ mrs x3, cntv_ctl_el0 and x3, x3, #3 str w3, [x0, #VCPU_TIMER_CNTV_CTL] - bic x3, x3, #1 // Clear Enable - msr cntv_ctl_el0, x3 isb @@ -571,6 +569,9 @@ str x3, [x0, #VCPU_TIMER_CNTV_CVAL] 1: + // Disable the virtual timer + msr cntv_ctl_el0, xzr + // Allow physical timer/counter access for the host mrs x2, cnthctl_el2 orr x2, x2, #3 -- cgit v1.2.3 From 34c3faa353db8f5d3ce9966cf854d5643c64c4db Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 15 Sep 2015 17:15:33 +0100 Subject: arm64: KVM: Remove all traces of the ThumbEE registers Although the ThumbEE registers and traps were present in earlier versions of the v8 architecture, it was retrospectively removed and so we can do the same. Whilst this breaks migrating a guest started on a previous version of the kernel, it is much better to kill these (non existent) registers as soon as possible. Reviewed-by: Marc Zyngier Signed-off-by: Will Deacon [maz: added commend about migration] Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_arm.h | 1 - arch/arm64/include/asm/kvm_asm.h | 4 +--- arch/arm64/kvm/hyp.S | 22 ++++------------------ arch/arm64/kvm/sys_regs.c | 7 ------- 4 files changed, 5 insertions(+), 29 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index cbc5e1a0ea8f..9694f2654593 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -172,7 +172,6 @@ #define VTTBR_VMID_MASK (UL(0xFF) << VTTBR_VMID_SHIFT) /* Hyp System Trap Register */ -#define HSTR_EL2_TTEE (1 << 16) #define HSTR_EL2_T(x) (1 << x) /* Hyp Coproccessor Trap Register Shifts */ diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 67fa0de3d483..5e377101f919 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -53,9 +53,7 @@ #define IFSR32_EL2 25 /* Instruction Fault Status Register */ #define FPEXC32_EL2 26 /* Floating-Point Exception Control Register */ #define DBGVCR32_EL2 27 /* Debug Vector Catch Register */ -#define TEECR32_EL1 28 /* ThumbEE Configuration Register */ -#define TEEHBR32_EL1 29 /* ThumbEE Handler Base Register */ -#define NR_SYS_REGS 30 +#define NR_SYS_REGS 28 /* 32bit mapping */ #define c0_MPIDR (MPIDR_EL1 * 2) /* MultiProcessor ID Register */ diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index 60a83e2900a7..85634777e160 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -433,20 +433,13 @@ mrs x5, ifsr32_el2 stp x4, x5, [x3] - skip_fpsimd_state x8, 3f + skip_fpsimd_state x8, 2f mrs x6, fpexc32_el2 str x6, [x3, #16] -3: - skip_debug_state x8, 2f +2: + skip_debug_state x8, 1f mrs x7, dbgvcr32_el2 str x7, [x3, #24] -2: - skip_tee_state x8, 1f - - add x3, x2, #CPU_SYSREG_OFFSET(TEECR32_EL1) - mrs x4, teecr32_el1 - mrs x5, teehbr32_el1 - stp x4, x5, [x3] 1: .endm @@ -466,16 +459,9 @@ msr dacr32_el2, x4 msr ifsr32_el2, x5 - skip_debug_state x8, 2f + skip_debug_state x8, 1f ldr x7, [x3, #24] msr dbgvcr32_el2, x7 -2: - skip_tee_state x8, 1f - - add x3, x2, #CPU_SYSREG_OFFSET(TEECR32_EL1) - ldp x4, x5, [x3] - msr teecr32_el1, x4 - msr teehbr32_el1, x5 1: .endm diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1d0463e6a9e3..d03d3af17e7e 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -539,13 +539,6 @@ static const struct sys_reg_desc sys_reg_descs[] = { { Op0(0b10), Op1(0b000), CRn(0b0111), CRm(0b1110), Op2(0b110), trap_dbgauthstatus_el1 }, - /* TEECR32_EL1 */ - { Op0(0b10), Op1(0b010), CRn(0b0000), CRm(0b0000), Op2(0b000), - NULL, reset_val, TEECR32_EL1, 0 }, - /* TEEHBR32_EL1 */ - { Op0(0b10), Op1(0b010), CRn(0b0001), CRm(0b0000), Op2(0b000), - NULL, reset_val, TEEHBR32_EL1, 0 }, - /* MDCCSR_EL1 */ { Op0(0b10), Op1(0b011), CRn(0b0000), CRm(0b0001), Op2(0b000), trap_raz_wi }, -- cgit v1.2.3 From ef748917b529847277f07c98c55e1c0ce416449f Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 2 Sep 2015 14:31:21 +0800 Subject: arm/arm64: KVM: Remove 'config KVM_ARM_MAX_VCPUS' This patch removes config option of KVM_ARM_MAX_VCPUS, and like other ARCHs, just choose the maximum allowed value from hardware, and follows the reasons: 1) from distribution view, the option has to be defined as the max allowed value because it need to meet all kinds of virtulization applications and need to support most of SoCs; 2) using a bigger value doesn't introduce extra memory consumption, and the help text in Kconfig isn't accurate because kvm_vpu structure isn't allocated until request of creating VCPU is sent from QEMU; 3) the main effect is that the field of vcpus[] in 'struct kvm' becomes a bit bigger(sizeof(void *) per vcpu) and need more cache lines to hold the structure, but 'struct kvm' is one generic struct, and it has worked well on other ARCHs already in this way. Also, the world switch frequecy is often low, for example, it is ~2000 when running kernel building load in VM from APM xgene KVM host, so the effect is very small, and the difference can't be observed in my test at all. Cc: Dann Frazier Signed-off-by: Ming Lei Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm/include/asm/kvm_host.h | 8 ++------ arch/arm/kvm/Kconfig | 11 ----------- arch/arm64/include/asm/kvm_host.h | 8 ++------ arch/arm64/kvm/Kconfig | 11 ----------- include/kvm/arm_vgic.h | 6 +----- virt/kvm/arm/vgic-v3.c | 2 +- 6 files changed, 6 insertions(+), 40 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index dcba0fa5176e..c8c226a19dbe 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -29,12 +29,6 @@ #define __KVM_HAVE_ARCH_INTC_INITIALIZED -#if defined(CONFIG_KVM_ARM_MAX_VCPUS) -#define KVM_MAX_VCPUS CONFIG_KVM_ARM_MAX_VCPUS -#else -#define KVM_MAX_VCPUS 0 -#endif - #define KVM_USER_MEM_SLOTS 32 #define KVM_PRIVATE_MEM_SLOTS 4 #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 @@ -44,6 +38,8 @@ #include +#define KVM_MAX_VCPUS VGIC_V2_MAX_CPUS + u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode); int __attribute_const__ kvm_target_cpu(void); int kvm_reset_vcpu(struct kvm_vcpu *vcpu); diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig index bfb915d05665..210eccadb69a 100644 --- a/arch/arm/kvm/Kconfig +++ b/arch/arm/kvm/Kconfig @@ -45,15 +45,4 @@ config KVM_ARM_HOST ---help--- Provides host support for ARM processors. -config KVM_ARM_MAX_VCPUS - int "Number maximum supported virtual CPUs per VM" - depends on KVM_ARM_HOST - default 4 - help - Static number of max supported virtual CPUs per VM. - - If you choose a high number, the vcpu structures will be quite - large, so only choose a reasonable number that you expect to - actually use. - endif # VIRTUALIZATION diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 415938dc45cf..3fb58ea944eb 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -30,12 +30,6 @@ #define __KVM_HAVE_ARCH_INTC_INITIALIZED -#if defined(CONFIG_KVM_ARM_MAX_VCPUS) -#define KVM_MAX_VCPUS CONFIG_KVM_ARM_MAX_VCPUS -#else -#define KVM_MAX_VCPUS 0 -#endif - #define KVM_USER_MEM_SLOTS 32 #define KVM_PRIVATE_MEM_SLOTS 4 #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 @@ -43,6 +37,8 @@ #include #include +#define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS + #define KVM_VCPU_MAX_FEATURES 3 int __attribute_const__ kvm_target_cpu(void); diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index bfffe8f4bd53..5c7e920e4861 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -41,15 +41,4 @@ config KVM_ARM_HOST ---help--- Provides host support for ARM processors. -config KVM_ARM_MAX_VCPUS - int "Number maximum supported virtual CPUs per VM" - depends on KVM_ARM_HOST - default 4 - help - Static number of max supported virtual CPUs per VM. - - If you choose a high number, the vcpu structures will be quite - large, so only choose a reasonable number that you expect to - actually use. - endif # VIRTUALIZATION diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index d901f1a47be6..4e14dac282bb 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -35,11 +35,7 @@ #define VGIC_V3_MAX_LRS 16 #define VGIC_MAX_IRQS 1024 #define VGIC_V2_MAX_CPUS 8 - -/* Sanity checks... */ -#if (KVM_MAX_VCPUS > 255) -#error Too many KVM VCPUs, the VGIC only supports up to 255 VCPUs for now -#endif +#define VGIC_V3_MAX_CPUS 255 #if (VGIC_NR_IRQS_LEGACY & 31) #error "VGIC_NR_IRQS must be a multiple of 32" diff --git a/virt/kvm/arm/vgic-v3.c b/virt/kvm/arm/vgic-v3.c index afbf925b00f4..7dd5d62f10a1 100644 --- a/virt/kvm/arm/vgic-v3.c +++ b/virt/kvm/arm/vgic-v3.c @@ -288,7 +288,7 @@ int vgic_v3_probe(struct device_node *vgic_node, vgic->vctrl_base = NULL; vgic->type = VGIC_V3; - vgic->max_gic_vcpus = KVM_MAX_VCPUS; + vgic->max_gic_vcpus = VGIC_V3_MAX_CPUS; kvm_info("%s@%llx IRQ%d\n", vgic_node->name, vcpu_res.start, vgic->maint_irq); -- cgit v1.2.3