Commit 7134fa07 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

Merge tag 'kvmarm-fixes-5.7-2' of... 

Merge tag 'kvmarm-fixes-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

KVM/arm fixes for Linux 5.7, take #2

- Fix compilation with Clang
- Correctly initialize GICv4.1 in the absence of a virtual ITS
- Move SP_EL0 save/restore to the guest entry/exit code
- Handle PC wrap around on 32bit guests, and narrow all 32bit
  registers on userspace access
parents 9e5e19f5 0225fd5e

arch/arm64/kvm/guest.c

+7 −0
Original line number Diff line number Diff line
@@ -200,6 +200,13 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) 
	}



	memcpy((u32 *)regs + off, valp, KVM_REG_SIZE(reg->id));



	if (*vcpu_cpsr(vcpu) & PSR_MODE32_BIT) {

		int i;



		for (i = 0; i < 16; i++)

			*vcpu_reg32(vcpu, i) = (u32)*vcpu_reg32(vcpu, i);

	}

out:

	return err;

}

arch/arm64/kvm/hyp/entry.S

+23 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 


#define CPU_GP_REG_OFFSET(x)	(CPU_GP_REGS + x)

#define CPU_XREG_OFFSET(x)	CPU_GP_REG_OFFSET(CPU_USER_PT_REGS + 8*x)

#define CPU_SP_EL0_OFFSET	(CPU_XREG_OFFSET(30) + 8)



	.text

	.pushsection	.hyp.text, "ax"
@@ -47,6 +48,16 @@ 
	ldp	x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]

.endm



.macro save_sp_el0 ctxt, tmp

	mrs	\tmp,	sp_el0

	str	\tmp,	[\ctxt, #CPU_SP_EL0_OFFSET]

.endm



.macro restore_sp_el0 ctxt, tmp

	ldr	\tmp,	  [\ctxt, #CPU_SP_EL0_OFFSET]

	msr	sp_el0, \tmp

.endm



/*

 * u64 __guest_enter(struct kvm_vcpu *vcpu,

 *		     struct kvm_cpu_context *host_ctxt);
@@ -60,6 +71,9 @@ SYM_FUNC_START(__guest_enter) 
	// Store the host regs

	save_callee_saved_regs x1



	// Save the host's sp_el0

	save_sp_el0	x1, x2



	// Now the host state is stored if we have a pending RAS SError it must

	// affect the host. If any asynchronous exception is pending we defer

	// the guest entry. The DSB isn't necessary before v8.2 as any SError
@@ -83,6 +97,9 @@ alternative_else_nop_endif 
	// when this feature is enabled for kernel code.

	ptrauth_switch_to_guest x29, x0, x1, x2



	// Restore the guest's sp_el0

	restore_sp_el0 x29, x0



	// Restore guest regs x0-x17

	ldp	x0, x1,   [x29, #CPU_XREG_OFFSET(0)]

	ldp	x2, x3,   [x29, #CPU_XREG_OFFSET(2)]
@@ -130,6 +147,9 @@ SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL) 
	// Store the guest regs x18-x29, lr

	save_callee_saved_regs x1



	// Store the guest's sp_el0

	save_sp_el0	x1, x2



	get_host_ctxt	x2, x3



	// Macro ptrauth_switch_to_guest format:
@@ -139,6 +159,9 @@ SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL) 
	// when this feature is enabled for kernel code.

	ptrauth_switch_to_host x1, x2, x3, x4, x5



	// Restore the hosts's sp_el0

	restore_sp_el0 x2, x3



	// Now restore the host regs

	restore_callee_saved_regs x2

arch/arm64/kvm/hyp/hyp-entry.S

+0 −1
Original line number Diff line number Diff line
@@ -198,7 +198,6 @@ SYM_CODE_END(__hyp_panic) 
.macro invalid_vector	label, target = __hyp_panic

	.align	2

SYM_CODE_START(\label)

\label:

	b \target

SYM_CODE_END(\label)

.endm

arch/arm64/kvm/hyp/sysreg-sr.c

+3 −14
Original line number Diff line number Diff line
@@ -15,8 +15,9 @@ 
/*

 * Non-VHE: Both host and guest must save everything.

 *

 * VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and pstate,

 * which are handled as part of the el2 return state) on every switch.

 * VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and

 * pstate, which are handled as part of the el2 return state) on every

 * switch (sp_el0 is being dealt with in the assembly code).

 * tpidr_el0 and tpidrro_el0 only need to be switched when going

 * to host userspace or a different VCPU.  EL1 registers only need to be

 * switched when potentially going to run a different VCPU.  The latter two
@@ -26,12 +27,6 @@ 
static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)

{

	ctxt->sys_regs[MDSCR_EL1]	= read_sysreg(mdscr_el1);



	/*

	 * The host arm64 Linux uses sp_el0 to point to 'current' and it must

	 * therefore be saved/restored on every entry/exit to/from the guest.

	 */

	ctxt->gp_regs.regs.sp		= read_sysreg(sp_el0);

}



static void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
@@ -99,12 +94,6 @@ NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe); 
static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)

{

	write_sysreg(ctxt->sys_regs[MDSCR_EL1],	  mdscr_el1);



	/*

	 * The host arm64 Linux uses sp_el0 to point to 'current' and it must

	 * therefore be saved/restored on every entry/exit to/from the guest.

	 */

	write_sysreg(ctxt->gp_regs.regs.sp,	  sp_el0);

}



static void __hyp_text __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)

virt/kvm/arm/hyp/aarch32.c

+6 −2
Original line number Diff line number Diff line
@@ -125,12 +125,16 @@ static void __hyp_text kvm_adjust_itstate(struct kvm_vcpu *vcpu) 
 */

void __hyp_text kvm_skip_instr32(struct kvm_vcpu *vcpu, bool is_wide_instr)

{

	u32 pc = *vcpu_pc(vcpu);

	bool is_thumb;



	is_thumb = !!(*vcpu_cpsr(vcpu) & PSR_AA32_T_BIT);

	if (is_thumb && !is_wide_instr)

		*vcpu_pc(vcpu) += 2;

		pc += 2;

	else

		*vcpu_pc(vcpu) += 4;

		pc += 4;



	*vcpu_pc(vcpu) = pc;



	kvm_adjust_itstate(vcpu);

}

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