From 9c5623e3e42e94927d02a6693875badf15692970 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Thu, 8 Nov 2007 18:19:20 +0200 Subject: [PATCH] KVM: VMX: Use vmx to inject real-mode interrupts Instead of injecting real-mode interrupts by writing the interrupt frame into guest memory, abuse vmx by injecting a software interrupt. We need to pretend the software interrupt instruction had a length > 0, so we have to adjust rip backward. This lets us not to mess with writing guest memory, which is complex and also sleeps. Signed-off-by: Avi Kivity --- drivers/kvm/vmx.c | 53 ++++------------------------------------------- drivers/kvm/vmx.h | 1 + 2 files changed, 5 insertions(+), 49 deletions(-) diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c index eca422e9506d..d2c25e25d3aa 100644 --- a/drivers/kvm/vmx.c +++ b/drivers/kvm/vmx.c @@ -1709,58 +1709,13 @@ out: return ret; } -static void inject_rmode_irq(struct kvm_vcpu *vcpu, int irq) -{ - u16 ent[2]; - u16 cs; - u16 ip; - unsigned long flags; - unsigned long ss_base = vmcs_readl(GUEST_SS_BASE); - u16 sp = vmcs_readl(GUEST_RSP); - u32 ss_limit = vmcs_read32(GUEST_SS_LIMIT); - - if (sp > ss_limit || sp < 6) { - vcpu_printf(vcpu, "%s: #SS, rsp 0x%lx ss 0x%lx limit 0x%x\n", - __FUNCTION__, - vmcs_readl(GUEST_RSP), - vmcs_readl(GUEST_SS_BASE), - vmcs_read32(GUEST_SS_LIMIT)); - return; - } - - if (emulator_read_std(irq * sizeof(ent), &ent, sizeof(ent), vcpu) != - X86EMUL_CONTINUE) { - vcpu_printf(vcpu, "%s: read guest err\n", __FUNCTION__); - return; - } - - flags = vmcs_readl(GUEST_RFLAGS); - cs = vmcs_readl(GUEST_CS_BASE) >> 4; - ip = vmcs_readl(GUEST_RIP); - - - if (emulator_write_emulated( - ss_base + sp - 2, &flags, 2, vcpu) != X86EMUL_CONTINUE || - emulator_write_emulated( - ss_base + sp - 4, &cs, 2, vcpu) != X86EMUL_CONTINUE || - emulator_write_emulated( - ss_base + sp - 6, &ip, 2, vcpu) != X86EMUL_CONTINUE) { - vcpu_printf(vcpu, "%s: write guest err\n", __FUNCTION__); - return; - } - - vmcs_writel(GUEST_RFLAGS, flags & - ~(X86_EFLAGS_IF | X86_EFLAGS_AC | X86_EFLAGS_TF)); - vmcs_write16(GUEST_CS_SELECTOR, ent[1]) ; - vmcs_writel(GUEST_CS_BASE, ent[1] << 4); - vmcs_writel(GUEST_RIP, ent[0]); - vmcs_writel(GUEST_RSP, (vmcs_readl(GUEST_RSP) & ~0xffff) | (sp - 6)); -} - static void vmx_inject_irq(struct kvm_vcpu *vcpu, int irq) { if (vcpu->rmode.active) { - inject_rmode_irq(vcpu, irq); + vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, + irq | INTR_TYPE_SOFT_INTR | INTR_INFO_VALID_MASK); + vmcs_write32(VM_ENTRY_INSTRUCTION_LEN, 1); + vmcs_writel(GUEST_RIP, vmcs_readl(GUEST_RIP) - 1); return; } vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, diff --git a/drivers/kvm/vmx.h b/drivers/kvm/vmx.h index c84bd3733153..d757b36c2fbe 100644 --- a/drivers/kvm/vmx.h +++ b/drivers/kvm/vmx.h @@ -233,6 +233,7 @@ enum vmcs_field { #define INTR_TYPE_EXT_INTR (0 << 8) /* external interrupt */ #define INTR_TYPE_EXCEPTION (3 << 8) /* processor exception */ +#define INTR_TYPE_SOFT_INTR (4 << 8) /* software interrupt */ /* * Exit Qualifications for MOV for Control Register Access -- 2.30.2