From 53af3ba2e8195f504d6a3a0667ccb5e7d4c57599 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Mon, 30 Jan 2017 21:21:51 +1100 Subject: [PATCH] KVM: PPC: Book3S HV: Allow guest exit path to have MMU on If we allow LPCR[AIL] to be set for radix guests, then interrupts from the guest to the host can be delivered by the hardware with relocation on, and thus the code path starting at kvmppc_interrupt_hv can be executed in virtual mode (MMU on) for radix guests (previously it was only ever executed in real mode). Most of the code is indifferent to whether the MMU is on or off, but the calls to OPAL that use the real-mode OPAL entry code need to be switched to use the virtual-mode code instead. The affected calls are the calls to the OPAL XICS emulation functions in kvmppc_read_one_intr() and related functions. We test the MSR[IR] bit to detect whether we are in real or virtual mode, and call the opal_rm_* or opal_* function as appropriate. The other place that depends on the MMU being off is the optimization where the guest exit code jumps to the external interrupt vector or hypervisor doorbell interrupt vector, or returns to its caller (which is __kvmppc_vcore_entry). If the MMU is on and we are returning to the caller, then we don't need to use an rfid instruction since the MMU is already on; a simple blr suffices. If there is an external or hypervisor doorbell interrupt to handle, we branch to the relocation-on version of the interrupt vector. Signed-off-by: Paul Mackerras Signed-off-by: Michael Ellerman --- arch/powerpc/kvm/book3s_hv_builtin.c | 38 +++++++++++++++++-------- arch/powerpc/kvm/book3s_hv_rm_xics.c | 8 ++---- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 29 +++++++++++++++++++ 3 files changed, 58 insertions(+), 17 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c index 5bb24be0b346..fe08fea54b70 100644 --- a/arch/powerpc/kvm/book3s_hv_builtin.c +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -29,6 +29,11 @@ #include #include +static bool in_realmode(void) +{ + return !(mfmsr() & MSR_IR); +} + #define KVM_CMA_CHUNK_ORDER 18 /* @@ -200,7 +205,6 @@ static inline void rm_writeb(unsigned long paddr, u8 val) /* * Send an interrupt or message to another CPU. - * This can only be called in real mode. * The caller needs to include any barrier needed to order writes * to memory vs. the IPI/message. */ @@ -226,7 +230,9 @@ void kvmhv_rm_send_ipi(int cpu) /* Else poke the target with an IPI */ xics_phys = paca[cpu].kvm_hstate.xics_phys; - if (xics_phys) + if (!in_realmode()) + opal_int_set_mfrr(get_hard_smp_processor_id(cpu), IPI_PRIORITY); + else if (xics_phys) rm_writeb(xics_phys + XICS_MFRR, IPI_PRIORITY); else opal_rm_int_set_mfrr(get_hard_smp_processor_id(cpu), @@ -412,14 +418,15 @@ static long kvmppc_read_one_intr(bool *again) /* Now read the interrupt from the ICP */ xics_phys = local_paca->kvm_hstate.xics_phys; - if (!xics_phys) { - /* Use OPAL to read the XIRR */ + rc = 0; + if (!in_realmode()) + rc = opal_int_get_xirr(&xirr, false); + else if (!xics_phys) rc = opal_rm_int_get_xirr(&xirr, false); - if (rc < 0) - return 1; - } else { + else xirr = _lwzcix(xics_phys + XICS_XIRR); - } + if (rc < 0) + return 1; /* * Save XIRR for later. Since we get control in reverse endian @@ -445,15 +452,19 @@ static long kvmppc_read_one_intr(bool *again) * If it is an IPI, clear the MFRR and EOI it. */ if (xisr == XICS_IPI) { - if (xics_phys) { + rc = 0; + if (!in_realmode()) { + opal_int_set_mfrr(hard_smp_processor_id(), 0xff); + rc = opal_int_eoi(h_xirr); + } else if (xics_phys) { _stbcix(xics_phys + XICS_MFRR, 0xff); _stwcix(xics_phys + XICS_XIRR, xirr); } else { opal_rm_int_set_mfrr(hard_smp_processor_id(), 0xff); rc = opal_rm_int_eoi(h_xirr); - /* If rc > 0, there is another interrupt pending */ - *again = rc > 0; } + /* If rc > 0, there is another interrupt pending */ + *again = rc > 0; /* * Need to ensure side effects of above stores @@ -471,7 +482,10 @@ static long kvmppc_read_one_intr(bool *again) /* We raced with the host, * we need to resend that IPI, bummer */ - if (xics_phys) + if (!in_realmode()) + opal_int_set_mfrr(hard_smp_processor_id(), + IPI_PRIORITY); + else if (xics_phys) _stbcix(xics_phys + XICS_MFRR, IPI_PRIORITY); else opal_rm_int_set_mfrr(hard_smp_processor_id(), diff --git a/arch/powerpc/kvm/book3s_hv_rm_xics.c b/arch/powerpc/kvm/book3s_hv_rm_xics.c index 06edc4366639..7e2eb3e865b3 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_xics.c +++ b/arch/powerpc/kvm/book3s_hv_rm_xics.c @@ -70,11 +70,9 @@ static inline void icp_send_hcore_msg(int hcore, struct kvm_vcpu *vcpu) hcpu = hcore << threads_shift; kvmppc_host_rm_ops_hv->rm_core[hcore].rm_data = vcpu; smp_muxed_ipi_set_message(hcpu, PPC_MSG_RM_HOST_ACTION); - if (paca[hcpu].kvm_hstate.xics_phys) - icp_native_cause_ipi_rm(hcpu); - else - opal_rm_int_set_mfrr(get_hard_smp_processor_id(hcpu), - IPI_PRIORITY); + kvmppc_set_host_ipi(hcpu, 1); + smp_mb(); + kvmhv_rm_send_ipi(hcpu); } #else static inline void icp_send_hcore_msg(int hcore, struct kvm_vcpu *vcpu) { } diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index dcc67a87d688..46c1c1fe55c8 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -148,6 +148,15 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) addi r1, r1, 112 ld r7, HSTATE_HOST_MSR(r13) + /* + * If we came back from the guest via a relocation-on interrupt, + * we will be in virtual mode at this point, which makes it a + * little easier to get back to the caller. + */ + mfmsr r0 + andi. r0, r0, MSR_IR /* in real mode? */ + bne .Lvirt_return + cmpwi cr1, r12, BOOK3S_INTERRUPT_MACHINE_CHECK cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL beq 11f @@ -181,6 +190,26 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) mtspr SPRN_HSRR1, r7 ba 0xe80 + /* Virtual-mode return - can't get here for HMI or machine check */ +.Lvirt_return: + cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL + beq 16f + cmpwi r12, BOOK3S_INTERRUPT_H_DOORBELL + beq 17f + andi. r0, r7, MSR_EE /* were interrupts hard-enabled? */ + beq 18f + mtmsrd r7, 1 /* if so then re-enable them */ +18: mtlr r8 + blr + +16: mtspr SPRN_HSRR0, r8 /* jump to reloc-on external vector */ + mtspr SPRN_HSRR1, r7 + b exc_virt_0x4500_hardware_interrupt + +17: mtspr SPRN_HSRR0, r8 + mtspr SPRN_HSRR1, r7 + b exc_virt_0x4e80_h_doorbell + kvmppc_primary_no_guest: /* We handle this much like a ceded vcpu */ /* put the HDEC into the DEC, since HDEC interrupts don't wake us */ -- 2.20.1