From: Paolo Bonzini <pbonzini@redhat.com>
To: Anup Patel <Anup.Patel@wdc.com>,
Palmer Dabbelt <palmer@sifive.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Radim K <rkrcmar@redhat.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>,
Atish Patra <Atish.Patra@wdc.com>,
Alistair Francis <Alistair.Francis@wdc.com>,
Damien Le Moal <Damien.LeMoal@wdc.com>,
Christoph Hellwig <hch@infradead.org>,
Anup Patel <anup@brainfault.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-riscv@lists.infradead.org"
<linux-riscv@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH 08/16] RISC-V: KVM: Handle MMIO exits for VCPU
Date: Tue, 30 Jul 2019 13:20:13 +0200 [thread overview]
Message-ID: <05d41219-6c0c-8851-dab6-24f9c76aed57@redhat.com> (raw)
In-Reply-To: <20190729115544.17895-9-anup.patel@wdc.com>
On 29/07/19 13:57, Anup Patel wrote:
> +static ulong get_insn(struct kvm_vcpu *vcpu)
> +{
> + ulong __sepc = vcpu->arch.guest_context.sepc;
> + ulong __hstatus, __sstatus, __vsstatus;
> +#ifdef CONFIG_RISCV_ISA_C
> + ulong rvc_mask = 3, tmp;
> +#endif
> + ulong flags, val;
> +
> + local_irq_save(flags);
> +
> + __vsstatus = csr_read(CSR_VSSTATUS);
> + __sstatus = csr_read(CSR_SSTATUS);
> + __hstatus = csr_read(CSR_HSTATUS);
> +
> + csr_write(CSR_VSSTATUS, __vsstatus | SR_MXR);
> + csr_write(CSR_SSTATUS, vcpu->arch.guest_context.sstatus | SR_MXR);
> + csr_write(CSR_HSTATUS, vcpu->arch.guest_context.hstatus | HSTATUS_SPRV);
> +
> +#ifndef CONFIG_RISCV_ISA_C
> + asm ("\n"
> +#ifdef CONFIG_64BIT
> + STR(LWU) " %[insn], (%[addr])\n"
> +#else
> + STR(LW) " %[insn], (%[addr])\n"
> +#endif
> + : [insn] "=&r" (val) : [addr] "r" (__sepc));
> +#else
> + asm ("and %[tmp], %[addr], 2\n"
> + "bnez %[tmp], 1f\n"
> +#ifdef CONFIG_64BIT
> + STR(LWU) " %[insn], (%[addr])\n"
> +#else
> + STR(LW) " %[insn], (%[addr])\n"
> +#endif
> + "and %[tmp], %[insn], %[rvc_mask]\n"
> + "beq %[tmp], %[rvc_mask], 2f\n"
> + "sll %[insn], %[insn], %[xlen_minus_16]\n"
> + "srl %[insn], %[insn], %[xlen_minus_16]\n"
> + "j 2f\n"
> + "1:\n"
> + "lhu %[insn], (%[addr])\n"
> + "and %[tmp], %[insn], %[rvc_mask]\n"
> + "bne %[tmp], %[rvc_mask], 2f\n"
> + "lhu %[tmp], 2(%[addr])\n"
> + "sll %[tmp], %[tmp], 16\n"
> + "add %[insn], %[insn], %[tmp]\n"
> + "2:"
> + : [vsstatus] "+&r" (__vsstatus), [insn] "=&r" (val),
> + [tmp] "=&r" (tmp)
> + : [addr] "r" (__sepc), [rvc_mask] "r" (rvc_mask),
> + [xlen_minus_16] "i" (__riscv_xlen - 16));
> +#endif
> +
> + csr_write(CSR_HSTATUS, __hstatus);
> + csr_write(CSR_SSTATUS, __sstatus);
> + csr_write(CSR_VSSTATUS, __vsstatus);
> +
> + local_irq_restore(flags);
> +
> + return val;
> +}
> +
This also needs fixups for exceptions, because the guest can race
against the host and modify its page tables concurrently with the
vmexit. (How effective this is, of course, depends on how the TLB is
implemented in hardware, but you need to do the safe thing anyway).
Paolo
next prev parent reply other threads:[~2019-07-30 11:20 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-29 11:56 [RFC PATCH 00/16] KVM RISC-V Support Anup Patel
2019-07-29 11:56 ` [RFC PATCH 01/16] KVM: RISC-V: Add KVM_REG_RISCV for ONE_REG interface Anup Patel
2019-07-29 11:56 ` [RFC PATCH 02/16] RISC-V: Add hypervisor extension related CSR defines Anup Patel
2019-07-29 11:56 ` [RFC PATCH 03/16] RISC-V: Add initial skeletal KVM support Anup Patel
2019-07-30 9:23 ` Paolo Bonzini
2019-07-30 11:04 ` Anup Patel
2019-07-30 9:25 ` Paolo Bonzini
2019-07-30 11:03 ` Anup Patel
2019-07-29 11:56 ` [RFC PATCH 04/16] RISC-V: KVM: Implement VCPU create, init and destroy functions Anup Patel
2019-07-30 8:48 ` Paolo Bonzini
2019-07-30 10:16 ` Paolo Bonzini
2019-07-30 11:45 ` Anup Patel
2019-07-30 11:47 ` Paolo Bonzini
2019-07-29 11:56 ` [RFC PATCH 05/16] RISC-V: KVM: Implement VCPU interrupts and requests handling Anup Patel
2019-07-30 11:17 ` Paolo Bonzini
2019-07-30 12:00 ` Anup Patel
2019-07-30 12:12 ` Paolo Bonzini
2019-07-30 12:45 ` Anup Patel
2019-07-30 13:18 ` Paolo Bonzini
2019-07-30 13:35 ` Anup Patel
2019-07-30 14:08 ` Paolo Bonzini
2019-08-02 3:59 ` Anup Patel
2019-07-29 11:56 ` [RFC PATCH 06/16] RISC-V: KVM: Implement KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls Anup Patel
2019-07-30 8:43 ` Paolo Bonzini
2019-07-30 9:35 ` Paolo Bonzini
2019-07-30 12:08 ` Anup Patel
2019-07-30 12:10 ` Paolo Bonzini
2019-07-30 12:16 ` Anup Patel
2019-07-29 11:57 ` [RFC PATCH 07/16] RISC-V: KVM: Implement VCPU world-switch Anup Patel
2019-07-30 9:34 ` Paolo Bonzini
2019-07-30 12:51 ` Anup Patel
2019-07-29 11:57 ` [RFC PATCH 08/16] RISC-V: KVM: Handle MMIO exits for VCPU Anup Patel
2019-07-30 11:20 ` Paolo Bonzini [this message]
2019-07-31 7:23 ` Anup Patel
2019-07-29 11:57 ` [RFC PATCH 09/16] RISC-V: KVM: Handle WFI " Anup Patel
2019-07-29 11:57 ` [RFC PATCH 10/16] RISC-V: KVM: Implement VMID allocator Anup Patel
2019-07-30 8:59 ` Paolo Bonzini
2019-07-29 11:57 ` [RFC PATCH 11/16] RISC-V: KVM: Implement stage2 page table programming Anup Patel
2019-07-30 9:00 ` Paolo Bonzini
2019-07-30 12:14 ` Anup Patel
2019-07-29 11:57 ` [RFC PATCH 12/16] RISC-V: KVM: Implement MMU notifiers Anup Patel
2019-07-29 11:57 ` [RFC PATCH 13/16] RISC-V: KVM: Add timer functionality Anup Patel
2019-07-29 14:40 ` Andreas Schwab
2019-07-29 18:02 ` Atish Patra
2019-07-30 6:51 ` Andreas Schwab
2019-07-30 7:00 ` Atish Patra
2019-07-30 11:26 ` Paolo Bonzini
2019-07-31 1:55 ` Atish Patra
2019-07-31 6:58 ` Paolo Bonzini
2019-07-31 7:18 ` Anup Patel
2019-07-29 11:57 ` [RFC PATCH 14/16] RISC-V: KVM: FP lazy save/restore Anup Patel
2019-07-29 11:57 ` [RFC PATCH 15/16] RISC-V: KVM: Add SBI v0.1 support Anup Patel
2019-07-29 19:40 ` Paolo Bonzini
2019-07-29 19:51 ` Atish Patra
2019-07-29 20:08 ` Paolo Bonzini
2019-07-29 21:08 ` Atish Patra
2019-07-30 9:26 ` Paolo Bonzini
2019-07-29 11:58 ` [RFC PATCH 16/16] RISC-V: Enable VIRTIO drivers in RV64 and RV32 defconfig Anup Patel
2019-07-29 21:47 ` [RFC PATCH 00/16] KVM RISC-V Support Paolo Bonzini
2019-07-30 5:26 ` Anup Patel
2019-07-30 11:33 ` Paolo Bonzini
2019-07-30 13:50 ` Anup Patel
2019-07-30 14:02 ` Paolo Bonzini
2019-07-30 6:53 ` Andreas Schwab
2019-07-30 7:25 ` Anup Patel
2019-07-30 7:42 ` Andreas Schwab
2019-07-30 7:36 ` Anup Patel
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