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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] x86/PV: split out dealing with CRn from privileged instruction handling
commit f745527379e414299732995cde221eeb7068f022
Author: Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Fri Sep 30 09:54:43 2016 +0200
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Sep 30 09:54:43 2016 +0200
x86/PV: split out dealing with CRn from privileged instruction handling
This is in preparation for using the generic emulator here.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
xen/arch/x86/traps.c | 196 ++++++++++++++++++++++++++++-----------------------
1 file changed, 107 insertions(+), 89 deletions(-)
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 24d173f..7618575 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -2254,6 +2254,107 @@ unsigned long guest_to_host_gpr_switch(unsigned long);
void (*pv_post_outb_hook)(unsigned int port, u8 value);
+static int priv_op_read_cr(unsigned int reg, unsigned long *val,
+ struct x86_emulate_ctxt *ctxt)
+{
+ const struct vcpu *curr = current;
+
+ switch ( reg )
+ {
+ case 0: /* Read CR0 */
+ *val = (read_cr0() & ~X86_CR0_TS) | curr->arch.pv_vcpu.ctrlreg[0];
+ return X86EMUL_OKAY;
+
+ case 2: /* Read CR2 */
+ case 4: /* Read CR4 */
+ *val = curr->arch.pv_vcpu.ctrlreg[reg];
+ return X86EMUL_OKAY;
+
+ case 3: /* Read CR3 */
+ {
+ const struct domain *currd = curr->domain;
+ unsigned long mfn;
+
+ if ( !is_pv_32bit_domain(currd) )
+ {
+ mfn = pagetable_get_pfn(curr->arch.guest_table);
+ *val = xen_pfn_to_cr3(mfn_to_gmfn(currd, mfn));
+ }
+ else
+ {
+ l4_pgentry_t *pl4e =
+
map_domain_page(_mfn(pagetable_get_pfn(curr->arch.guest_table)));
+
+ mfn = l4e_get_pfn(*pl4e);
+ unmap_domain_page(pl4e);
+ *val = compat_pfn_to_cr3(mfn_to_gmfn(currd, mfn));
+ }
+ /* PTs should not be shared */
+ BUG_ON(page_get_owner(mfn_to_page(mfn)) == dom_cow);
+ return X86EMUL_OKAY;
+ }
+ }
+
+ return X86EMUL_UNHANDLEABLE;
+}
+
+static int priv_op_write_cr(unsigned int reg, unsigned long val,
+ struct x86_emulate_ctxt *ctxt)
+{
+ struct vcpu *curr = current;
+
+ switch ( reg )
+ {
+ case 0: /* Write CR0 */
+ if ( (val ^ read_cr0()) & ~X86_CR0_TS )
+ {
+ gdprintk(XENLOG_WARNING,
+ "Attempt to change unmodifiable CR0 flags\n");
+ break;
+ }
+ do_fpu_taskswitch(!!(val & X86_CR0_TS));
+ return X86EMUL_OKAY;
+
+ case 2: /* Write CR2 */
+ curr->arch.pv_vcpu.ctrlreg[2] = val;
+ arch_set_cr2(curr, val);
+ return X86EMUL_OKAY;
+
+ case 3: /* Write CR3 */
+ {
+ struct domain *currd = curr->domain;
+ unsigned long gfn;
+ struct page_info *page;
+ int rc;
+
+ gfn = !is_pv_32bit_domain(currd)
+ ? xen_cr3_to_pfn(val) : compat_cr3_to_pfn(val);
+ page = get_page_from_gfn(currd, gfn, NULL, P2M_ALLOC);
+ if ( !page )
+ break;
+ rc = new_guest_cr3(page_to_mfn(page));
+ put_page(page);
+
+ switch ( rc )
+ {
+ case 0:
+ return X86EMUL_OKAY;
+ case -ERESTART: /* retry after preemption */
+ return X86EMUL_RETRY;
+ }
+ break;
+ }
+
+ case 4: /* Write CR4 */
+ curr->arch.pv_vcpu.ctrlreg[4] = pv_guest_cr4_fixup(curr, val);
+ write_cr4(pv_guest_cr4_to_real_cr4(curr));
+ ctxt_switch_levelling(curr);
+ return X86EMUL_OKAY;
+ }
+
+ return X86EMUL_UNHANDLEABLE;
+}
+
static inline uint64_t guest_misc_enable(uint64_t val)
{
val &= ~(MSR_IA32_MISC_ENABLE_PERF_AVAIL |
@@ -2666,48 +2767,9 @@ static int emulate_privileged_op(struct cpu_user_regs
*regs)
goto fail;
modrm_reg += ((opcode >> 3) & 7) + (lock << 3);
modrm_rm |= (opcode >> 0) & 7;
- reg = decode_register(modrm_rm, regs, 0);
- switch ( modrm_reg )
- {
- case 0: /* Read CR0 */
- *reg = (read_cr0() & ~X86_CR0_TS) |
- v->arch.pv_vcpu.ctrlreg[0];
- break;
-
- case 2: /* Read CR2 */
- *reg = v->arch.pv_vcpu.ctrlreg[2];
- break;
-
- case 3: /* Read CR3 */
- {
- unsigned long mfn;
-
- if ( !is_pv_32bit_domain(currd) )
- {
- mfn = pagetable_get_pfn(v->arch.guest_table);
- *reg = xen_pfn_to_cr3(mfn_to_gmfn(currd, mfn));
- }
- else
- {
- l4_pgentry_t *pl4e =
-
map_domain_page(_mfn(pagetable_get_pfn(v->arch.guest_table)));
-
- mfn = l4e_get_pfn(*pl4e);
- unmap_domain_page(pl4e);
- *reg = compat_pfn_to_cr3(mfn_to_gmfn(currd, mfn));
- }
- /* PTs should not be shared */
- BUG_ON(page_get_owner(mfn_to_page(mfn)) == dom_cow);
- }
- break;
-
- case 4: /* Read CR4 */
- *reg = v->arch.pv_vcpu.ctrlreg[4];
- break;
-
- default:
+ if ( priv_op_read_cr(modrm_reg, decode_register(modrm_rm, regs, 0),
+ NULL) != X86EMUL_OKAY )
goto fail;
- }
break;
case 0x21: /* MOV DR?,<reg> */ {
@@ -2731,56 +2793,12 @@ static int emulate_privileged_op(struct cpu_user_regs
*regs)
modrm_reg += ((opcode >> 3) & 7) + (lock << 3);
modrm_rm |= (opcode >> 0) & 7;
reg = decode_register(modrm_rm, regs, 0);
- switch ( modrm_reg )
+ switch ( priv_op_write_cr(modrm_reg, *reg, NULL) )
{
- case 0: /* Write CR0 */
- if ( (*reg ^ read_cr0()) & ~X86_CR0_TS )
- {
- gdprintk(XENLOG_WARNING,
- "Attempt to change unmodifiable CR0 flags.\n");
- goto fail;
- }
- (void)do_fpu_taskswitch(!!(*reg & X86_CR0_TS));
- break;
-
- case 2: /* Write CR2 */
- v->arch.pv_vcpu.ctrlreg[2] = *reg;
- arch_set_cr2(v, *reg);
- break;
-
- case 3: {/* Write CR3 */
- unsigned long gfn;
- struct page_info *page;
-
- gfn = !is_pv_32bit_domain(currd)
- ? xen_cr3_to_pfn(*reg) : compat_cr3_to_pfn(*reg);
- page = get_page_from_gfn(currd, gfn, NULL, P2M_ALLOC);
- if ( page )
- {
- rc = new_guest_cr3(page_to_mfn(page));
- put_page(page);
- }
- else
- rc = -EINVAL;
-
- switch ( rc )
- {
- case 0:
- break;
- case -ERESTART: /* retry after preemption */
- goto skip;
- default: /* not okay */
- goto fail;
- }
+ case X86EMUL_OKAY:
break;
- }
-
- case 4: /* Write CR4 */
- v->arch.pv_vcpu.ctrlreg[4] = pv_guest_cr4_fixup(v, *reg);
- write_cr4(pv_guest_cr4_to_real_cr4(v));
- ctxt_switch_levelling(v);
- break;
-
+ case X86EMUL_RETRY: /* retry after preemption */
+ goto skip;
default:
goto fail;
}
--
generated by git-patchbot for /home/xen/git/xen.git#master
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