linux_dsm_epyc7002/arch/arm64/kvm/hyp/debug-sr.c
Christoffer Dall 014c4c77aa KVM: arm64: Improve debug register save/restore flow
Instead of having multiple calls from the world switch path to the debug
logic, each figuring out if the dirty bit is set and if we should
save/restore the debug registers, let's just provide two hooks to the
debug save/restore functionality, one for switching to the guest
context, and one for switching to the host context, and we get the
benefit of only having to evaluate the dirty flag once on each path,
plus we give the compiler some more room to inline some of this
functionality.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:12 +00:00

206 lines
5.9 KiB
C

/*
* Copyright (C) 2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/compiler.h>
#include <linux/kvm_host.h>
#include <asm/debug-monitors.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#define read_debug(r,n) read_sysreg(r##n##_el1)
#define write_debug(v,r,n) write_sysreg(v, r##n##_el1)
#define save_debug(ptr,reg,nr) \
switch (nr) { \
case 15: ptr[15] = read_debug(reg, 15); \
case 14: ptr[14] = read_debug(reg, 14); \
case 13: ptr[13] = read_debug(reg, 13); \
case 12: ptr[12] = read_debug(reg, 12); \
case 11: ptr[11] = read_debug(reg, 11); \
case 10: ptr[10] = read_debug(reg, 10); \
case 9: ptr[9] = read_debug(reg, 9); \
case 8: ptr[8] = read_debug(reg, 8); \
case 7: ptr[7] = read_debug(reg, 7); \
case 6: ptr[6] = read_debug(reg, 6); \
case 5: ptr[5] = read_debug(reg, 5); \
case 4: ptr[4] = read_debug(reg, 4); \
case 3: ptr[3] = read_debug(reg, 3); \
case 2: ptr[2] = read_debug(reg, 2); \
case 1: ptr[1] = read_debug(reg, 1); \
default: ptr[0] = read_debug(reg, 0); \
}
#define restore_debug(ptr,reg,nr) \
switch (nr) { \
case 15: write_debug(ptr[15], reg, 15); \
case 14: write_debug(ptr[14], reg, 14); \
case 13: write_debug(ptr[13], reg, 13); \
case 12: write_debug(ptr[12], reg, 12); \
case 11: write_debug(ptr[11], reg, 11); \
case 10: write_debug(ptr[10], reg, 10); \
case 9: write_debug(ptr[9], reg, 9); \
case 8: write_debug(ptr[8], reg, 8); \
case 7: write_debug(ptr[7], reg, 7); \
case 6: write_debug(ptr[6], reg, 6); \
case 5: write_debug(ptr[5], reg, 5); \
case 4: write_debug(ptr[4], reg, 4); \
case 3: write_debug(ptr[3], reg, 3); \
case 2: write_debug(ptr[2], reg, 2); \
case 1: write_debug(ptr[1], reg, 1); \
default: write_debug(ptr[0], reg, 0); \
}
static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
{
u64 reg;
/* Clear pmscr in case of early return */
*pmscr_el1 = 0;
/* SPE present on this CPU? */
if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
ID_AA64DFR0_PMSVER_SHIFT))
return;
/* Yes; is it owned by EL3? */
reg = read_sysreg_s(SYS_PMBIDR_EL1);
if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
return;
/* No; is the host actually using the thing? */
reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT)))
return;
/* Yes; save the control register and disable data generation */
*pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
write_sysreg_s(0, SYS_PMSCR_EL1);
isb();
/* Now drain all buffered data to memory */
psb_csync();
dsb(nsh);
}
static void __hyp_text __debug_restore_spe_nvhe(u64 pmscr_el1)
{
if (!pmscr_el1)
return;
/* The host page table is installed, but not yet synchronised */
isb();
/* Re-enable data generation */
write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
}
static void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu,
struct kvm_guest_debug_arch *dbg,
struct kvm_cpu_context *ctxt)
{
u64 aa64dfr0;
int brps, wrps;
aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
brps = (aa64dfr0 >> 12) & 0xf;
wrps = (aa64dfr0 >> 20) & 0xf;
save_debug(dbg->dbg_bcr, dbgbcr, brps);
save_debug(dbg->dbg_bvr, dbgbvr, brps);
save_debug(dbg->dbg_wcr, dbgwcr, wrps);
save_debug(dbg->dbg_wvr, dbgwvr, wrps);
ctxt->sys_regs[MDCCINT_EL1] = read_sysreg(mdccint_el1);
}
static void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu,
struct kvm_guest_debug_arch *dbg,
struct kvm_cpu_context *ctxt)
{
u64 aa64dfr0;
int brps, wrps;
aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
brps = (aa64dfr0 >> 12) & 0xf;
wrps = (aa64dfr0 >> 20) & 0xf;
restore_debug(dbg->dbg_bcr, dbgbcr, brps);
restore_debug(dbg->dbg_bvr, dbgbvr, brps);
restore_debug(dbg->dbg_wcr, dbgwcr, wrps);
restore_debug(dbg->dbg_wvr, dbgwvr, wrps);
write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1);
}
void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *host_ctxt;
struct kvm_cpu_context *guest_ctxt;
struct kvm_guest_debug_arch *host_dbg;
struct kvm_guest_debug_arch *guest_dbg;
/*
* Non-VHE: Disable and flush SPE data generation
* VHE: The vcpu can run, but it can't hide.
*/
if (!has_vhe())
__debug_save_spe_nvhe(&vcpu->arch.host_debug_state.pmscr_el1);
if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY))
return;
host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
guest_ctxt = &vcpu->arch.ctxt;
host_dbg = &vcpu->arch.host_debug_state.regs;
guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
__debug_save_state(vcpu, host_dbg, host_ctxt);
__debug_restore_state(vcpu, guest_dbg, guest_ctxt);
}
void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *host_ctxt;
struct kvm_cpu_context *guest_ctxt;
struct kvm_guest_debug_arch *host_dbg;
struct kvm_guest_debug_arch *guest_dbg;
if (!has_vhe())
__debug_restore_spe_nvhe(vcpu->arch.host_debug_state.pmscr_el1);
if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY))
return;
host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
guest_ctxt = &vcpu->arch.ctxt;
host_dbg = &vcpu->arch.host_debug_state.regs;
guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
__debug_save_state(vcpu, guest_dbg, guest_ctxt);
__debug_restore_state(vcpu, host_dbg, host_ctxt);
vcpu->arch.debug_flags &= ~KVM_ARM64_DEBUG_DIRTY;
}
u32 __hyp_text __kvm_get_mdcr_el2(void)
{
return read_sysreg(mdcr_el2);
}