From patchwork Fri Dec 2 05:46:40 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [v2] KVM: PPC: Avoid patching paravirt template code From: Liu Yu-B13201 X-Patchwork-Id: 128804 Message-Id: <1322804800-25654-1-git-send-email-yu.liu@freescale.com> To: Cc: , Liu Yu Date: Fri, 2 Dec 2011 13:46:40 +0800 Currently we patch the whole code include paravirt template code. This isn't safe for scratch area and has impact to performance. Signed-off-by: Liu Yu --- v2: exclude the entire template region in the main loop arch/powerpc/kernel/kvm.c | 9 ++++++++- arch/powerpc/kernel/kvm_emul.S | 6 ++++++ 2 files changed, 14 insertions(+), 1 deletions(-) diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c index 3953fbd..a63b371 100644 --- a/arch/powerpc/kernel/kvm.c +++ b/arch/powerpc/kernel/kvm.c @@ -665,6 +665,9 @@ static void kvm_check_ins(u32 *inst, u32 features) } } +extern u32 kvm_template_start[]; +extern u32 kvm_template_end[]; + static void kvm_use_magic_page(void) { u32 *p; @@ -692,8 +695,12 @@ static void kvm_use_magic_page(void) */ local_irq_disable(); - for (p = start; p < end; p++) + for (p = start; p < end; p++) { + /* Avoid patching the template code */ + if (p >= kvm_template_start && p < kvm_template_end) + p = kvm_template_end; kvm_check_ins(p, features); + } local_irq_enable(); diff --git a/arch/powerpc/kernel/kvm_emul.S b/arch/powerpc/kernel/kvm_emul.S index 801058d..e291cf3 100644 --- a/arch/powerpc/kernel/kvm_emul.S +++ b/arch/powerpc/kernel/kvm_emul.S @@ -66,6 +66,9 @@ kvm_hypercall_start: shared->critical == r1 and r2 is always != r1 */ \ STL64(r2, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0); +.global kvm_template_start +kvm_template_start: + .global kvm_emulate_mtmsrd kvm_emulate_mtmsrd: @@ -350,3 +353,6 @@ kvm_emulate_mtsrin_orig_ins_offs: .global kvm_emulate_mtsrin_len kvm_emulate_mtsrin_len: .long (kvm_emulate_mtsrin_end - kvm_emulate_mtsrin) / 4 + +.global kvm_template_end +kvm_template_end: